import java.io.*;
import java.util.*;
import java.util.function.*;
import java.util.stream.*;

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