#include <bits/stdc++.h>
using namespace std;
const long long INF = 1000000000000000;
int main(){
  int N, M;
  cin >> N >> M;
  vector<vector<int>> A(N, vector<int>(M));
  for (int i = 0; i < N; i++){
    for (int j = 0; j < M; j++){
      cin >> A[i][j];
    }
  }
  if (N == 1){
    cout << 0 << endl;
  } else {
    vector<vector<long long>> dp(N, vector<long long>(M, INF));
    for (int i = 0; i < M; i++){
      dp[0][i] = A[0][i];
    }
    for (int i = 0; i < N - 1; i++){
      for (int j = 0; j < M; j++){
        dp[i + 1][j] = min(dp[i + 1][j], dp[i][j] + A[i + 1][j]);
      }
      long long mn = INF;
      for (int j = 0; j < M; j++){
        mn = min(mn, dp[i + 1][j]);
      }
      for (int j = 0; j < M; j++){
        dp[i + 1][j] = min(dp[i + 1][j], mn + A[i + 1][j]);
      }
    }
    long long ans = INF;
    for (int i = 0; i < M; i++){
      ans = min(ans, dp[N - 1][i]);
    }
    cout << ans << endl;
  }
}