import java.util.*; 
import java.io.*;
import java.math.*;
import java.util.stream.*;
import java.util.function.*;
import java.security.SecureRandom;

class Main implements Runnable
{ 

    void solve()
    {  
        int H = in.nextInt() , W = in.nextInt();
        long [][] grid = new long[H + 2][W + 2];
        for(int i = 1 ; i < H + 1 ; i ++ )
        {
            for(int j = 1 ; j < W + 1 ; j ++ )
            {
                grid[i][j] = in.nextLong();
            }
        }
        List<IntPair> position = new ArrayList<>();
        for(int i = 0 ; i < H + 2 ; i ++ )
        {
            for(int j = 0 ; j < W + 2 ; j ++ )
            {
                if(i == 0 || j == 0 || i == H + 1 || j == W + 1)
                {
                    position.add(new IntPair(i , j));
                }
            }
        }
        List<Set<IntPair>> [] P = new ArrayList[position.size()];
        for(int i = 0 ; i < position.size() ; i ++ ) P[i] = new ArrayList<>();
        for(int i = 0 ; i < position.size() ; i ++ )
        {
            for(int dir = 0 ; dir < 8 ; dir ++ )
            {
                int y = position.get(i).fi , x = position.get(i).se ;
                int [][] used = new int[H + 2][W + 2];
                used[y][x] = 1 ;
                HashSet<IntPair> box = new HashSet<>();
                y += dy8[dir] ; x += dx8[dir] ;
                while(x > 0 && x < W + 1 && y > 0 && y < H + 1)
                {
                    box.add(new IntPair(y , x));
                    y += dy8[dir] ; x += dx8[dir] ;
                }
                P[i].add(box);
            }
        }
        long max = 0 ;
        for(int i = 0 ; i < position.size() ; i ++ )
        {
            for(int j = i + 1 ; j < position.size() ; j ++ )
            {
                for(int k = 0 ; k < 8 ; k ++ )
                {
                    for(int l = 0 ; l < 8 ; l ++ )
                    {
                        long sum = 0 ;
                        int [][] used = new int[H + 2][W + 2];
                        used[position.get(i).fi][position.get(i).se] = 1 ;
                        used[position.get(j).fi][position.get(j).se] = 1 ;
                        Set<IntPair> or = new HashSet<>(P[i].get(k));
                        or.addAll(P[j].get(l));
                        for(IntPair v : or) sum += grid[v.fi][v.se];
                        max = max(max , sum);
                    }
                }
            }
        }
        out.println(max);
    }   

    public static void main(String[] args) 
    {
        new Thread(null, new Main(), "", Runtime.getRuntime().maxMemory()).start(); 
    }

    public void run() 
    {   
        solve();
        out.flush();
    }
    boolean is_over(int y , int x , int H , int W ) { return y < 0 || y >= H || x < 0 || x >= W ; }
    public record IntPair(int fi , int se) { public String toString() { return fi +" "+ se ;} }
    public record LongPair(long fi , long se) { public String toString() { return fi +" "+ se ;} }
    public record Edge(int to , long weight) { }
    public record State(int now , long dist) { }
    public double dist(LongPair p1 , LongPair p2) { return Math.sqrt((p1.fi - p2.fi) * (p1.fi - p2.fi) + (p1.se - p2.se) * (p1.se - p2.se)); }
    public int max(int ... a) { int max = -1 ; for(int p : a) max = Math.max(max , p); return max; }
    public int min(int ... a) { int min = Integer.MAX_VALUE ; for(int p : a) min = Math.min(min , p); return min; }
    public long max(long ... a) { long max = -1 ; for(long p : a) max = Math.max(max , p); return max; }
    public long min(long ... a) { long min = Long.MAX_VALUE ; for(long p : a) min = Math.min(min , p); return min; }
    public int sum(int ... a) { int sum = 0 ; for(int p : a) sum += p ; return sum ;}
    public long sum(long ... a) { long sum = 0 ; for(long p : a) sum += p ; return sum ;}
    public int abs(int a , int b) { return (int) Math.abs(a - b) ; }
    public long abs(long a , long b) { return (long) Math.abs(a - b) ; }
    public int pow(int a , int b) { return (int) Math.pow(a , b) ; }
    public long pow(long a , long b) { return (long) Math.pow(a , b) ; }
    public long rec(long a) { return a == 1 ? 1 : a * rec(a - 1); }
    public int [] rev(int [] a) { int [] r = new int[a.length] ; int idx = a.length ; for(int p : a) r[--idx] = p ; return r ; }
    public long [] rev(long [] a) { long [] r = new long[a.length] ; int idx = a.length ; for(long p : a) r[--idx] = p ; return r ; }
    public int gcd(int a, int b) { return b == 0 ? a: gcd(b, a % b); }
    public int lcm(int a, int b) { return a / gcd(a, b) * b; }
    public long gcd(long a, long b) { return b == 0 ? a: gcd(b, a % b); }
    public long lcm(long a, long b) { return a / gcd(a, b) * b; }
    public int gcd(int ... a) { int gcd = 0 ; for(int p : a) gcd = gcd(gcd , p) ; return gcd ; }
    public long gcd(long ... a) { long gcd = 0L ; for(long p : a) gcd = gcd(gcd , p) ; return gcd ; }
    public int lcm(int ... a) { int lcm = 1 ; for(int p : a) lcm = lcm(lcm , p) ; return lcm ; }
    public long lcm(long ... a) { long lcm = 1 ; for(long p : a) lcm = lcm(lcm , p) ; return lcm ; }
    public BigInteger lcm(BigInteger... arr) { return Stream.of(arr).reduce((x, y) -> lcm(x, y)).orElse(BigInteger.ONE); }
    public BigInteger gcd(BigInteger[] arr) { return Stream.of(arr).reduce(BigInteger::gcd).orElse(BigInteger.ZERO); }
    public BigInteger lcm(BigInteger x, BigInteger y) { return x.multiply(y).divide(Objects.nonNull(gcd(x, y)) ? gcd(x, y) : BigInteger.ONE); }
    public BigInteger gcd(BigInteger x, BigInteger y) { return (Objects.nonNull(x) ? x : BigInteger.ONE).gcd(y); }
    public char upper(char c) { return (char)('A' + (c - 'a')); }
    public char lower(char c) { return (char)('a' + (c - 'A')); }
    public void yn(boolean a) { out.println(a ? yes : no); }
    public String rev(String a) { return new StringBuilder(a).reverse().toString(); }
    public void fill(int [] a , int v) { Arrays.fill(a , v); }
    public void fill(long [] a , long v) { Arrays.fill(a , v); }
    public void fill(int [][] a , int v) { for(int [] aa : a) fill(aa , v) ; }
    public void fill(long [][] a , long v) { for(long [] aa : a) fill(aa , v) ; }
    public void fill(int [][][] a , int v) { for(int [][] aa : a) fill(aa , v); }
    public void fill(long [][][] a , long v) { for(long [][] aa : a) fill(aa , v); }
    public int [] copy(int [] a) { return Arrays.copyOf(a , a.length); } 
    public long [] copy(long [] a) { return Arrays.copyOf(a , a.length); } 
    public String bin(long a , int len) { String b = Long.toBinaryString(a); while(b.length() < len) b = "0" + b ; return b ; }
    public void debug(int [] a) { out.println(Arrays.toString(a)); fl();}
    public void debug(long [] a) { out.println(Arrays.toString(a)); fl();}
    public void debug(double [] a) { out.println(Arrays.toString(a)); fl();}
    public void debug(String [] a) { out.println(Arrays.toString(a)); fl();}
    public void debug(char [] a) { out.println(Arrays.toString(a)); fl();}
    public void debug(boolean [] a) { char [] c = conv(a); debug(c); fl();}
    public void debug(int [][] a) { for(int i = 0 ; i < a.length ; i ++ ) out.println(Arrays.toString(a[i])); fl();}
    public void debug(long [][] a) { for(int i = 0 ; i < a.length ; i ++ ) out.println(Arrays.toString(a[i])); fl();}
    public void debug(double [][] a) { for(int i = 0 ; i < a.length ; i ++ ) out.println(Arrays.toString(a[i])); fl();}
    public void debug(String [][] a) { for(int i = 0 ; i < a.length ; i ++ ) out.println(Arrays.toString(a[i])); fl();}
    public void debug(char [][] a) { for(int i = 0 ; i < a.length ; i ++ ) out.println(Arrays.toString(a[i])); fl();}
    public void debug(boolean [][] a) { char [][] c = new char [a.length][a[0].length] ; for(int i = 0 ; i < a.length ; i ++ ) c[i] = conv(a[i]) ; debug(c); fl();}
    private char [] conv(boolean [] a) { char [] c = new char[a.length] ; for(int i = 0 ; i < a.length ; i ++ ) c[i] = a[i] ? 'O' : 'X' ; return c ; }
    private void fl() { out.flush(); }
    public List<Integer> [] Graph(int n) { List<Integer> [] G = new ArrayList[n]; for(int i = 0 ; i < n ; i ++ ) G[i] = new ArrayList<>(); return G ; }
    public List<Edge> [] GraphW(int n) { List<Edge> [] G = new ArrayList[n]; for(int i = 0 ; i < n ; i ++ ) G[i] = new ArrayList<>(); return G ; }
    public mint pow(long a, long b , long mod) 
    {
        long res = 1;
        while (b > 0) 
        {
            if ((b & 1) != 0) 
            {
                res = (res * a) % mod ;
            }
            a = (a * a) % mod ;
            b >>= 1;
        }
        return new mint(res , mod);
    }
    public mint [] rec(int n , long mod) { mint [] r = new mint[n + 1]; r[0] = new mint(1 , mod); for(int i = 1 ; i <= n ; i ++ ) r[i] = r[i - 1].multiply(new mint(i + 1, mod)); return r ; }
    public PrintWriter out = new PrintWriter(System.out);
    public In in = new In();
    public final long MOD7 = 1000000007;
    public final long MOD9 = 998244353;
    public final int  inf = (1  << 30);
    public final long lnf = (1L << 60);
    public final String yes = "Yes";
    public final String no  = "No" ;
    public final char [] dir = {'U','R','D','L'};
    public final int [] dy4 = {-1,0,1,0};
    public final int [] dx4 = {0,1,0,-1};
    public final int [] dy8 = {-1,-1,-1,0,1,1,1,0};
    public final int [] dx8 = {-1,0,1,1,1,0,-1,-1};

}

class mint {
    
    private long value;
    private final long MOD;

    public mint(long value, long MOD) {
        this.MOD = MOD;
        this.value = (value % MOD + MOD) % MOD;
    }

    public mint add(mint other) {
        return new mint((this.value + other.value) % MOD, MOD);
    }

    public mint subtract(mint other) {
        return new mint((this.value - other.value + MOD) % MOD, MOD);
    }

    public mint multiply(mint other) {
        return new mint((this.value * other.value) % MOD, MOD);
    }

    public mint inverse() {
        return new mint(pow(this.value, MOD - 2), MOD);
    }

    public mint divide(mint other) {
        return this.multiply(other.inverse());
    }

    private long pow(long a, long b) {
        long res = 1;
        while (b > 0) {
            if ((b & 1) != 0) {
                res = (res * a) % MOD;
            }
            a = (a * a) % MOD;
            b >>= 1;
        }
        return res;
    }

    public long getVal() {
        return value;
    }

    @Override
    public String toString() {
        return String.valueOf(value);
    }
}

class Bigmint {

    private BigInteger mod;

    public Bigmint(long mod) 
    {
        this.mod = convert(mod);
    }

    public BigInteger add(long a, long b) 
    {
        BigInteger A = convert(a) , B = convert(b);
        return A.add(B).mod(mod);
    }

    public BigInteger subtract(long a, long b) 
    {
        BigInteger A = convert(a) , B = convert(b);
        return A.subtract(B).mod(mod);
    }

    public BigInteger multiply(long a, long b) 
    {
        BigInteger A = convert(a) , B = convert(b);
        return A.multiply(B).mod(mod);
    }

    public BigInteger divide(long a, long b) 
    {
        BigInteger A = convert(a) , B = convert(b);
        BigInteger inverseB = B.modInverse(mod);
        return A.multiply(inverseB).mod(mod);
    }

    private BigInteger convert(long a)
    {
        return new BigInteger(Long.toString(a));
    }
}

class SegmentTree
{
    private int n ;
    private long init ;
    private long [] tree ;
    private int size ;
    private BinaryOperator<Long> op ;

    SegmentTree(int size , long init , BinaryOperator<Long> op)
    {
        this.size = size;
        this.init = init ;
        this.op = op ;
        n = 1 ;
        while(n <= size) n *= 2 ;
        this.tree = new long[2 * n];
        for(int i = 0 ; i < 2 * n ; i ++ ) tree[i] = init ;
    }
    void update(int index , long value)
    {
        index += n ;
        tree[index] = value ;
        while(index > 0)
        {
            index /= 2 ;
            tree[index] = op.apply(tree[2 * index] , tree[2 * index + 1]);
        }
    }
    long query(int l , int r)
    {
        l += n ; r += n ;
        long res = init ;
        while(l < r)
        {
            if(l % 2 == 1){ res = op.apply(res , tree[l]) ; l ++ ; }
            l /= 2 ;
            if(r % 2 == 1){ res = op.apply(res , tree[r - 1]) ; r -- ; }
            r /= 2 ;
        }
        return res ;
    }
    void debug() 
    {
        for(int i = n ; i < n + size ; i ++ ) 
        {
            System.out.print(tree[i]+" ");
        }
        System.out.println();
    }
}

class LazySegmentTree 
{
    private long[] Dat;
    private long[] Laz;
    private int N;
    private long E0;
    private long E1;
    private LongBinaryOperator F;
    private LongBinaryOperator G;
    private LongBinaryOperator H;
    private LongBinaryOperator P;
    private int[] Stack = new int[64];
    //初期配列 , dat(関与しない値) , lazy(関与しない値) , dat() , dat&lazy() , lazy() , lazy*len()
    public LazySegmentTree(int n, long e0, long e1, LongBinaryOperator f, LongBinaryOperator g, LongBinaryOperator h, LongBinaryOperator p) 
    {
        this.E0 = e0;
        this.E1 = e1;
        this.F = f; this.G = g; this.H = h; this.P = p;
        int k = 1;
        while (k <= n) k <<= 1;
        this.Dat = new long[k << 1];
        this.Laz = new long[k << 1];
        this.N = k;
        Arrays.fill(Dat, E0);
        Arrays.fill(Laz, E1);
    }
    public LazySegmentTree(long[] src, long e0, long e1, LongBinaryOperator f, LongBinaryOperator g, LongBinaryOperator h, LongBinaryOperator p) 
    {
        this(src.length, e0, e1, f, g, h, p);
        build(src);
    }
    private void build(long[] src) 
    {
        System.arraycopy(src, 0, Dat, N, src.length);
        for (int i = N - 1; i > 0; i--) Dat[i] = F.applyAsLong(Dat[i << 1 | 0], Dat[i << 1 | 1]);
    }
    public void update(int l, int r, long v) 
    {
        if (l >= r) return;
        int m = updown(l, r);
        l += N; r += N;
        for (; l < r; l >>= 1, r >>= 1) 
        {
            if ((l & 1) != 0) {Laz[l] = H.applyAsLong(Laz[l], v); l++;}
            if ((r & 1) != 0) {r--; Laz[r] = H.applyAsLong(Laz[r], v);}
        }
        for (int i = 0; i < m; i++) 
        {
            int k = Stack[i];
            Dat[k] = F.applyAsLong(calcDat(k << 1 | 0), calcDat(k << 1 | 1));
        }
    }
    public long query(int i) 
    {
        int k = 1;
        int l = 0, r = N;
        while (k < N) 
        {
            int kl = k << 1 | 0;
            int kr = k << 1 | 1;
            Dat[k] = F.applyAsLong(calcDat(kl), calcDat(kr));
            int m = (l + r) >> 1;
            if (m > i) {r = m; k = kl;} 
            else {l = m; k = kr;}
        }
        return Dat[k];
    }
    public long query(int l, int r) 
    {
        if (l >= r) return E0;
        updown(l, r);
        long resL = E0, resR = E0;
        for (l += N, r += N; l < r; l >>= 1, r >>= 1) 
        {
            if ((l & 1) != 0) resL = F.applyAsLong(resL, calcDat(l++));
            if ((r & 1) != 0) resR = F.applyAsLong(calcDat(--r), resR);
        }
        return F.applyAsLong(resL, resR);
    }
    private int updown(int l, int r) 
    {
        if (l >= r) return 0;
        int i = 0;
        int kl = l + N, kr = r + N;
        for (int x = kl / (kl & -kl) >> 1, y = kr / (kr & -kr) >> 1; 0 < kl && kl < kr; kl >>= 1, kr >>= 1) 
        {
            if (kl <= x) Stack[i++] = kl;
            if (kr <= y) Stack[i++] = kr;
        }
        for (; kl > 0; kl >>= 1) Stack[i++] = kl;
        int m = i;
        while (i > 0) calcDat(Stack[--i]);
        return m;
    }
    private long calcDat(int k) 
    {
        long lz = Laz[k];
        if (lz != E1) 
        {
            int w = N / Integer.highestOneBit(k);
            Dat[k] = G.applyAsLong(Dat[k], P.applyAsLong(lz, w));
            if (k < N) 
            {
                int l = k << 1 | 0, r = k << 1 | 1;
                Laz[l] = H.applyAsLong(Laz[l], lz);
                Laz[r] = H.applyAsLong(Laz[r], lz);
            }
            Laz[k] = E1;
        }
        return Dat[k];
    }
    void debug()
    {
        for(int i = Dat.length - N ; i < Dat.length - 1; i ++ ) 
        {
            System.out.print(Dat[i]+" ");
        }
        System.out.println();
    }
}

class In
{

    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }

    private int readByte() { 
        if (hasNextByte()) return buffer[ptr++]; else return -1;
    }

    private static boolean isPrintableChar(int c) { 
        return 33 <= c && c <= 126;
    }

    private  boolean hasNext() { 
        while(hasNextByte() && !isPrintableChar(buffer[ptr])) {
            ptr++; 
        }
        return hasNextByte();
    }

    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }

    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }

    public double nextDouble() { 
        return Double.parseDouble(next());
    }

    public char nextChar() {
        return next().charAt(0);
    }
    
    public int [] IntArray(int n) {
        final int [] Array = new int [n];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = nextInt();
        }
        return Array;
    }
    public int [][] IntArray(int n , int m) {
        final int [][] Array = new int [n][m];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = IntArray(m);
        }
        return Array;
    }   
    public long [] LongArray(int n) {
        final long [] Array = new long [n];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = nextLong();
        }
        return Array;
    }
    public long [][] LongArray(int n , int m) {
        final long [][] Array = new long [n][m];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = LongArray(m);
        }
        return Array;
    }
    public String [] StringArray(int n) {
        final String [] Array = new String [n];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = next();
        }
        return Array;
    }
    public char [] CharArray(int n) {
        final char [] Array = new char[n];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = next().charAt(0);
        }
        return Array;
    }
    public char [][] CharArray(int n , int m) {
        final char [][] Array = new char [n][m];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = next().toCharArray();
        }
        return Array;
    }
    public char [][] CharArray2(int n , int m) {
        final char [][] Array = new char [n][m];
        for(int i = 0 ; i < n ; i ++ ) {
            for(int j = 0 ; j < m ; j ++ ) {
                Array[i][j] = next().charAt(0);
            }
        }
        return Array;
    }
    
}