using Lib;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using static Lib.Functions;
using static Lib.OutputLib;
public class Solver
{
    const bool MultiTestCase = false;
    void Solve()
    {
        checked
        {
            int h = ri, w = ri, n = ri;
            ReadArray(out (int a, int b)[] ab, n, () => (ri - 1, ri - 1));

            var uf = new UnionFind(h + w);
            foreach (var (a, b) in ab) uf.Unite(a, h + b);

            var vs = new List<(int a, int b)>();
            var ca = new int[h + w];
            var cb = new int[h + w];
            for (int i = 0; i < h; i++) ca[uf.Root(i)]++;
            for (int i = 0; i < w; i++) cb[uf.Root(h + i)]++;
            for (int i = 0; i < h + w; i++)
            {
                if (uf.Root(i) != i) continue;
                vs.Add((ca[i], cb[i]));
            }

            int fa = 0, fb = 0;
            foreach (var (a, b) in vs)
            {
                if (a == 0) { fb += b; continue; }
                if (b == 0) { fa += a; continue; }
            }

            var dp_min = new long[h + 1]; Array.Fill(dp_min, IINF);
            var dp_max = new long[h + 1]; Array.Fill(dp_max, -IINF);
            for (int i = 0; i <= fa; i++)
            {
                dp_min[i] = 0;
                dp_max[i] = fb;
            }
            foreach (var (a, b) in vs)
            {
                if (a == 0 || b == 0) continue;
                for (int i = h - a; i >= 0; i--)
                {
                    Chmin(ref dp_min[i + a], dp_min[i] + b);
                    Chmax(ref dp_max[i + a], dp_max[i] + b);
                }
            }

            long ans = 0;
            for (int i = 0; i <= h; i++)
            {
                long c = h - 2 * i;
                long u = (long)i * w, v;
                v = dp_min[i];
                if (0 <= v && v <= w) Chmax(ref ans, c * v + u);
                v = dp_max[i];
                if (0 <= v && v <= w) Chmax(ref ans, c * v + u);
            }

            Write(ans);
        }
    }

#pragma warning disable CS0162
    public Solver() { if (!MultiTestCase) Solve(); else for (int t = ri; t > 0; t--) Solve(); }
#pragma warning restore CS0162

    const int IINF = 1 << 30;
    const long INF = 1L << 60;
    int ri { [MethodImpl(256)] get => (int)sc.Integer(); }
    long rl { [MethodImpl(256)] get => sc.Integer(); }
    uint rui { [MethodImpl(256)] get => (uint)sc.UInteger(); }
    ulong rul { [MethodImpl(256)] get => sc.UInteger(); }
    double rd { [MethodImpl(256)] get => sc.Double(); }
    string rs { [MethodImpl(256)] get => sc.Scan(); }
    string rline { [MethodImpl(256)] get => sc.Line(); }
    public StreamScanner sc = new StreamScanner(Console.OpenStandardInput());
    void ReadArray(out int[] a, int n) { a = new int[n]; for (int i = 0; i < a.Length; i++) a[i] = ri; }
    void ReadArray(out long[] a, int n) { a = new long[n]; for (int i = 0; i < a.Length; i++) a[i] = rl; }
    void ReadArray<T>(out T[] a, int n, Func<T> read) { a = new T[n]; for (int i = 0; i < a.Length; i++) a[i] = read(); }
    void ReadArray<T>(out T[] a, int n, Func<int, T> read) { a = new T[n]; for (int i = 0; i < a.Length; i++) a[i] = read(i); }
}

static class Program
{
    static public void Main(string[] args)
    {
        SourceExpander.Expander.Expand();
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        new Solver();
        Console.Out.Flush();
    }
}
#region Expanded by https://github.com/kzrnm/SourceExpander
public class UnionFind{int n;int[]p,sz;public int GroupCount{get;private set;}public UnionFind(int _n){n=_n;GroupCount=n;p=new int[n];sz=new int[n];for(int i=0;i<n;i++){p[i]=i;sz[i]=1;}}public void Clear(){for(int i=0;i<n;i++){p[i]=i;sz[i]=1;}}public int Root(int x){if(p[x]==x)return x;return p[x]=Root(p[x]);}public int Size(int x)=>sz[Root(x)];public bool IsSame(int x,int y)=>Root(x)==Root(y);public bool Unite(int x,int y){int rx=Root(x),ry=Root(y);if(rx==ry)return false;p[ry]=rx;sz[rx]+=sz[ry];GroupCount--;return true;}public int[][]GetGroups(){var leader_buf=new int[n];var group_size=new int[n];int group_count=0;for(int i=0;i<n;i++){leader_buf[i]=Root(i);if(leader_buf[i]==i)group_count++;group_size[leader_buf[i]]++;}var result=new int[n][];for(int i=0;i<n;i++)result[i]=new int[group_size[i]];var idx=new int[n];for(int i=0;i<n;i++)result[leader_buf[i]][idx[leader_buf[i]]++]=i;var res=new int[group_count][];for(int i=0,j=0;i<n;i++)if(leader_buf[i]==i)res[j++]=result[i];return res;}}
namespace Lib{public static class Functions{[MethodImpl(256)]public static int Popcount(ulong x){x=(x&0x5555555555555555UL)+((x>>1)&0x5555555555555555UL);x=(x&0x3333333333333333UL)+((x>>2)&0x3333333333333333UL);x=(x&0x0f0f0f0f0f0f0f0fUL)+((x>>4)&0x0f0f0f0f0f0f0f0fUL);x=(x&0x00ff00ff00ff00ffUL)+((x>>8)&0x00ff00ff00ff00ffUL);x=(x&0x0000ffff0000ffffUL)+((x>>16)&0x0000ffff0000ffffUL);x=(x&0x00000000ffffffffUL)+((x>>32)&0x00000000ffffffffUL);return(int)x;}[MethodImpl(256)]public static int Popcount(long x){x=(x&0x5555555555555555L)+((x>>1)&0x5555555555555555L);x=(x&0x3333333333333333L)+((x>>2)&0x3333333333333333L);x=(x&0x0f0f0f0f0f0f0f0fL)+((x>>4)&0x0f0f0f0f0f0f0f0fL);x=(x&0x00ff00ff00ff00ffL)+((x>>8)&0x00ff00ff00ff00ffL);x=(x&0x0000ffff0000ffffL)+((x>>16)&0x0000ffff0000ffffL);x=(x&0x00000000ffffffffL)+((x>>32)&0x00000000ffffffffL);return(int)x;}[MethodImpl(256)]public static int Popcount(int x){x=(x&0x55555555)+((x>>1)&0x55555555);x=(x&0x33333333)+((x>>2)&0x33333333);x=(x&0x0f0f0f0f)+((x>>4)&0x0f0f0f0f);x=(x&0x00ff00ff)+((x>>8)&0x00ff00ff);x=(x&0x0000ffff)+((x>>16)&0x0000ffff);return x;}[MethodImpl(256)]public static int Ctz(long x){if(x==0)return-1;return Popcount((ulong)((x&-x)-1));}[MethodImpl(256)]public static int CeilPow2(int n){int x=0;while((1<<x)<n)x++;return x;}[MethodImpl(256)]public static int SafeMod(int x,int m){int r=x%m;return r<0?r+Math.Abs(m):r;}[MethodImpl(256)]public static long SafeMod(long x,long m){long r=x%m;return r<0?r+Math.Abs(m):r;}[MethodImpl(256)]public static bool IsIncreasing(long a,long b,long c)=>a<=b&&b<=c;[MethodImpl(256)]public static int Sign(long x)=>x==0?0:(x<0?-1:1);[MethodImpl(256)]public static int Sign(double x)=>x==0?0:(x<0?-1:1);[MethodImpl(256)]public static int DigitSum(long n,int d=10){long s=0;while(n>0){s+=n%d;n/=d;}return(int)s;}[MethodImpl(256)]public static long Floor(long a,long b)=>a>=0?a/b:(a+1)/b-1;[MethodImpl(256)]public static long Ceil(long a,long b)=>a>0?(a-1)/b+1:a/b;[MethodImpl(256)]public static int Gcd(int a,int b)=>b==0?a:Gcd(b,a%b);[MethodImpl(256)]public static uint Gcd(uint a,uint b)=>b==0?a:Gcd(b,a%b);[MethodImpl(256)]public static long Gcd(long a,long b)=>b==0?a:Gcd(b,a%b);[MethodImpl(256)]public static ulong Gcd(ulong a,ulong b)=>b==0?a:Gcd(b,a%b);[MethodImpl(256)]public static(long x,long y,long g)ExtGcd(long a,long b){if(b==0)return(Sign(a),0,Math.Abs(a));long c=SafeMod(a,b);var(x2,y2,g)=ExtGcd(b,c);long x=SafeMod(y2,b);long y=(g-a*x)/b;return(x,y,g);}[MethodImpl(256)]public static void Swap(ref int x,ref int y){x^=y;y^=x;x^=y;}[MethodImpl(256)]public static void Swap(ref long x,ref long y){x^=y;y^=x;x^=y;}[MethodImpl(256)]public static void Swap<T>(ref T x,ref T y){T t=y;y=x;x=t;}[MethodImpl(256)]public static T Clamp<T>(T x,T l,T r)where T:IComparable<T> =>x.CompareTo(l)<=0?l:(x.CompareTo(r)<=0?x:r);[MethodImpl(256)]public static T Clamp<T>(ref T x,T l,T r)where T:IComparable<T> =>x=x.CompareTo(l)<=0?l:(x.CompareTo(r)<=0?x:r);[MethodImpl(256)]public static void Chmin<T>(ref T x,T y)where T:IComparable<T>{if(x.CompareTo(y)>0)x=y;}[MethodImpl(256)]public static void Chmax<T>(ref T x,T y)where T:IComparable<T>{if(x.CompareTo(y)<0)x=y;}[MethodImpl(256)]public static int LowerBound(long[]arr,long val,int l=-1,int r=-1)=>LowerBound(arr.AsSpan(),t=>Sign(t-val),l,r);[MethodImpl(256)]public static int LowerBound(int[]arr,int val,int l=-1,int r=-1)=>LowerBound(arr.AsSpan(),t=>t-val,l,r);[MethodImpl(256)]public static int LowerBound<T>(T[]arr,T val,int l=-1,int r=-1)where T:IComparable<T> =>LowerBound(arr.AsSpan(),t=>t.CompareTo(val),l,r);[MethodImpl(256)]public static int LowerBound<T>(T[]arr,Func<T,int>comp,int l=-1,int r=-1)=>LowerBound(arr.AsSpan(),comp,l,r);[MethodImpl(256)]public static int LowerBound<T>(Span<T>data,Func<T,int>comp,int l=-1,int r=-1){if(data.Length==0)return-1;if(l==-1)l=0;if(r==-1)r=data.Length;while(l<r){int x=(l+r)/2;if(comp(data[x])<0)l=x+1;else r=x;}return l;}[MethodImpl(256)]public static int RangeCount<T>(T[]arr,T geq,T lt,int l=-1,int r=-1)where T:IComparable<T> =>Math.Max(0,LowerBound(arr.AsSpan(),t=>t.CompareTo(lt),l,r)-LowerBound(arr.AsSpan(),t=>t.CompareTo(geq),l,r));[MethodImpl(256)]public static string ToBase2(long v,int digit=-1){if(digit==-1){digit=0;while((v>>digit)>0)digit++;}var c=new string[digit];for(int i=0;i<digit;i++)c[digit-1-i]=((v>>i)&1)==0?"0":"1";return string.Join("",c);}[MethodImpl(256)]public static string ToBaseN(long v,int n,int digit=-1){if(digit==-1){digit=0;long pow=1;while(v>=pow){digit++;pow*=n;}}var c=new int[digit];for(int i=0;i<digit;i++,v/=n)c[digit-1-i]=(int)(v%n);return string.Join("",c);}}}
namespace Lib{public partial class StreamScanner{public int[][]ReadUnweightedTree(int n,int origin=1){var gr=new List<int>[n];for(int i=0;i<n;i++)gr[i]=new List<int>();for(int i=0;i<n-1;i++){int u=(int)(Integer()-origin);int v=(int)(Integer()-origin);gr[u].Add(v);gr[v].Add(u);}var g=new int[n][];for(int i=0;i<n;i++)g[i]=gr[i].ToArray();return g;}}}
namespace Lib{public partial class StreamScanner{public StreamScanner(Stream stream){str=stream;}private readonly Stream str;private readonly byte[]buf=new byte[1024];private int len,ptr;public bool isEof=false;public bool IsEndOfStream{get{return isEof;}}[MethodImpl(256)]private byte Read(){if(isEof)throw new EndOfStreamException();if(ptr>=len){ptr=0;if((len=str.Read(buf,0,1024))<=0){isEof=true;return 0;}}return buf[ptr++];}[MethodImpl(256)]public char Char(){byte b=0;do b=Read();while(b<33||126<b);return(char)b;}[MethodImpl(256)]public string Line(){var sb=new StringBuilder();for(var b=Char();b!=10&&!isEof;b=(char)Read())sb.Append(b);return sb.ToString();}[MethodImpl(256)]public string Scan(){var sb=new StringBuilder();for(var b=Char();b>=33&&b<=126;b=(char)Read())sb.Append(b);return sb.ToString();}[MethodImpl(256)]public long Integer(){long ret=0;byte b=0;var ng=false;do b=Read();while(b!='-'&&(b<'0'||'9'<b));if(b=='-'){ng=true;b=Read();}for(;true;b=Read()){if(b<'0'||'9'<b)return ng?-ret:ret;else ret=ret*10+b-'0';}}[MethodImpl(256)]public ulong UInteger(){ulong ret=0;byte b=0;do b=Read();while(b<'0'||'9'<b);for(;true;b=Read()){if(b<'0'||'9'<b)return ret;else ret=ret*10+b-'0';}}[MethodImpl(256)]public double Double()=>double.Parse(Scan());}}
namespace Lib{public static class OutputLib{[MethodImpl(256)]public static void WriteJoin<T>(string s,IEnumerable<T>t)=>Console.WriteLine(string.Join(s,t));[MethodImpl(256)]public static void WriteMat<T>(T[,]a,string sep=" "){int sz1=a.GetLength(0),sz2=a.GetLength(1);var b=new T[sz2];for(int i=0;i<sz1;i++){for(int j=0;j<sz2;j++)b[j]=a[i,j];WriteJoin(sep,b);}}[MethodImpl(256)]public static void WriteMat<T>(T[][]a,string sep=" "){for(int i=0;i<a.Length;i++)WriteJoin(sep,a[i]);}[MethodImpl(256)]public static void WriteMat<T>(T[][]a,Func<T,string>map,string sep=" "){for(int i=0;i<a.Length;i++)WriteJoin(sep,a[i].Select(x=>map(x)));}[MethodImpl(256)]public static void Write(object t)=>Console.WriteLine(t.ToString());[MethodImpl(256)]public static void Write(params object[]arg)=>Console.WriteLine(string.Join(" ",arg.Select(x=>x.ToString())));[MethodImpl(256)]public static void Write(string str)=>Console.WriteLine(str);[MethodImpl(256)]public static void WriteFlush(object t){Console.WriteLine(t.ToString());Console.Out.Flush();}[MethodImpl(256)]public static void WriteError(object t)=>Console.Error.WriteLine(t.ToString());[MethodImpl(256)]public static void Flush()=>Console.Out.Flush();[MethodImpl(256)]public static void YN(bool t)=>Console.WriteLine(t?"YES":"NO");[MethodImpl(256)]public static void Yn(bool t)=>Console.WriteLine(t?"Yes":"No");[MethodImpl(256)]public static void yn(bool t)=>Console.WriteLine(t?"yes":"no");[MethodImpl(256)]public static void DeleteLine()=>Console.Write("\x1b[1A\x1b[2K");[MethodImpl(256)]public static void ProgressBar(long now,long total,int blocks=50){int x=(int)((2*now*blocks+1)/(2*total));Console.Write($"\x1b[G[\x1b[42m{string.Concat(Enumerable.Repeat("_",x))}\x1b[0m{string.Concat(Enumerable.Repeat("_",blocks-x))}] : {now} / {total}");}}}
namespace SourceExpander{public class Expander{[Conditional("EXP")]public static void Expand(string inputFilePath=null,string outputFilePath=null,bool ignoreAnyError=true){}public static string ExpandString(string inputFilePath=null,bool ignoreAnyError=true){return "";}}}
#endregion Expanded by https://github.com/kzrnm/SourceExpander