TableCloth653.cpp

#include <iostream>
#include <list>
#include <limits.h>//for int_max
using namespace std;

int main() {
	int arr[51][51];
	int n, m;
	while (cin >> n >> m) {
		if (n == 0 && m == 0)
			break;
		bool flag = true;
		for (int i = 1; i <= n; i++) {
			if (!flag) {
				cin.ignore(int_max, '\n');// need to do this because you have to clear the buffer for the next input.
				//don't do cin.ignore(int_max), that would clear buffer till eof and other inputs will be skipped.
				continue;
			}
			for (int j = 1; j <= m; j++) {
				cin >> arr[i][j];
				if (arr[i][j] == 1) {
					if (i == 1 || i == n || j == 1 || j == m) {
						flag = false;
						cin.ignore(int_max, '\n');
						break;
					}
				}
			}
			
		}
		if (flag)
			cout << 4 << endl;
		else
			cout << 2 << endl;

	}
	return 0;
}