#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using i128 = __int128;
const int inf = 1e9;
const ll INF = 1e18; //❄️
int main() {
    ios::sync_with_stdio(0); cin.tie(0); 
    int n, m; cin >> n >> m;
    vector<vector<int>> dp(n, vector<int>(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cin >> dp[i][j];
        }
    }
    for (int i = 1; i < n; i++) {
        dp[i][0] += dp[i - 1][0];
    }
    for (int i = 1; i < m; i++) {
        dp[0][i] += dp[0][i - 1];
    }
    for (int i = 1; i < n; i++) {
        for (int j = 1; j < m; j++) {
            dp[i][j] = min(dp[i - 1][j], dp[i][j - 1]) + dp[i][j];
        }
    }
    cout << dp[n - 1][m - 1] << '\n';
    return 0;
}