#include<iostream>
#include<cstring>
using namespace std;
const int N=5005;
int dp[N][N];
int main(void)
{
    memset(dp,0x3f3f3f,sizeof(dp));
    int n,m;
    cin>>n>>m;
    dp[0][1]=0;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            cin>>dp[i][j];
            dp[i][j]=min(dp[i-1][j],dp[i][j-1])+dp[i][j];
        }
    }
    cout<<dp[n][m];
    return 0;
}