#include <bits/stdc++.h>

using namespace std;

const int N = 2e3 + 5;
int n, m, gz[N][N], dp[N];

int main() {
	cin >> n >> m;
	for (int i = 1; i <= m; i++) {
		for (int j = 1; j <= n; j++) {
			cin >> gz[i][j];
		}
	}

	int ans = INT_MAX;
	for (int i = 1; i <= m; i++) {
		memset(dp, 0, sizeof(dp));
		int hnext = i;
		dp[1] = gz[i][1];
		for (int j = 1; j < n; j++) {
			int z = hnext + 1;
			if (hnext == m) z = 1;
			dp[j + 1] = min(gz[hnext][j + 1], gz[z][j + 1]) + dp[j];
			if (dp[j + 1] == gz[z][j + 1] + dp[j]) hnext = z;
		}
		ans = min(ans, dp[n]);
	}

	cout << ans;

	return 0;
}