#include <iostream>
#include <algorithm>
#include <cstring>
#include <climits>

#define int long long

using namespace std;

const int N = 2010;

int n, m, dp[N][N];

int ans = LONG_LONG_MAX;

signed main() {
  cin >> m >> n;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      cin >> dp[i][j];
    }
  }
  for (int j = 2; j <= m; j++) {
    for (int i = 1; i <= n; i++) {
      if(i == n){
        dp[i][j] += min(dp[i][j - 1], dp[1][j - 1]);
      }
      else {
        dp[i][j] += min(dp[i][j - 1], dp[i + 1][j - 1]);
      }
    }
  }
  for (int i = 1; i <= n; i++) {
    ans = min(ans, dp[i][m]);
  }
  cout << ans << '\n';
  return 0;
}