// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using pii = pair<int, int>;
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define repr(i, n) for (int i = (int)(n - 1); i >= 0; --i)

int main() {
    int n, m;
    cin >> n >> m;
    vvi a(n, vi(m));
    rep(i, n) rep(j, m) cin >> a[i][j];
    if (n == 1) {
        cout << 0 << endl;
    } else {
        vector<vector<ll>> dp(n + 1, vector<ll>(m));
        rep(i, n) {
            rep(j, m) dp[i + 1][j] = dp[i][j] + a[i][j];
            ll mi = *min_element(dp[i + 1].begin(), dp[i + 1].end());
            rep(j, m) dp[i + 1][j] = min(dp[i + 1][j], mi + a[i][j]);
        }
        ll ret = *min_element(dp[n].begin(), dp[n].end());
        cout << ret << endl;
    }
    return 0;
}