import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        if (n == 1) {
            System.out.println(0);
            return;
        }
        long[][] dp = new long[n][m];
        for (int i = 0; i < m; i++) {
            dp[0][i] = sc.nextInt();
        }
        for (int i = 1; i < n; i++) {
            int[] values = new int[m];
            long min = Long.MAX_VALUE;
            for (int j = 0; j < m; j++) {
                values[j] = sc.nextInt();
                dp[i][j] = dp[i - 1][j] + values[j];
                min = Math.min(min, dp[i][j]);
            }
            for (int j = 0; j < m; j++) {
                dp[i][j] = Math.min(dp[i][j], min + values[j]);
            }
        }
        long ans = Long.MAX_VALUE;
        for (long x : dp[n - 1]) {
            ans = Math.min(ans, x);
        }
        System.out.println(ans);
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}