#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,m;
    cin >> n >>m;
    vector<vector<int> >arr(n,vector<int>(m));
    for(int i = 0;i < n;i++)
    {
        for(int j = 0;j < m;j++)
        {
            cin >> arr[i][j];
        }
    }
    vector<vector<int> >dp(n,vector<int>(m,0));
    dp[0][0] = arr[0][0];
    for(int i = 1;i < n;i++)dp[i][0] =dp[i-1][0] + arr[i][0];
    for(int j = 1;j < m;j++)dp[0][j] =dp[0][j-1] + arr[0][j];
    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]) + arr[i][j];
        }
    }
    cout<<dp[n-1][m-1];
    return 0;
    
}