#include <bits/stdc++.h>

using namespace std;
const int INF = 0x3f3f3f3f;

const int N = 110;
int n, m;
int a[N][N];
int res = INF;
int f[N][N];
/*
动态规划
2 3
1 3 5
2 4 6

答案：
13
*/

int main() {
    memset(f, 0x3f, sizeof f);

    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            cin >> a[i][j];

    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++) {
            if (i == 1 && j == 1)
                f[i][j] = a[i][j];
            else
                f[i][j] = min(f[i - 1][j], f[i][j - 1]) + a[i][j];
        }

    printf("%d\n", f[n][m]);
    return 0;
}