#include <bits/stdc++.h>

using namespace std;

int main()
{

    int n, m;
    cin >> n >> m;
    vector<vector<int>> a(n, vector<int>(m, 0));
    vector<vector<int>> dp(n+1, vector<int>(m+1, 0));

    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < m; j++)
        {
            cin >> a[i][j];
        }
    }
    dp[1][1] = a[0][0];
    for(int i = 1; i < n + 1; i++)
    {
        for(int j = 1; j < m + 1; j++)
        {
            if(j != 1 and i != 1)
            {
                dp[i][j] = min(dp[i-1][j], dp[i][j-1]) + a[i-1][j-1];
            }
            else if(j == 1 and i != 1)
            {
                dp[i][j] = dp[i-1][j] + a[i-1][j-1];
            }
            else if(j != 1 and i == 1)
            {
                dp[i][j] = dp[i][j-1] + a[i-1][j-1];
            }
        }
    }

    cout << dp[n][m];
}