DP matrix

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define fastio ios_base::sync_with_stdio(0); cin.tie(0)

const int N = 1e3 + 5;

int a[N][N] , dp[N][N];

signed main()
{
    fastio;

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


    /*
    1 2 1
    1 9 9
    9 9 1

    */
}