#include <bits/stdc++.h>
using namespace std;
char c[10007][10007];
int main() {
	int n;
	int ct = 0;
	cin >> n;
	for (int i = 1; i <= 8; ++i) {
		for (int j = 1; j <= n; ++j) {
			cin >> c[i][j];
		}
	}
	for (int i = 1; i <= 8; ++i) {
		for (int j = 1; j <= n; ++j) {
			if (c[i][j] == c[i][j - 1])  {
				cout << 1;
				break;
			} else {
				++ct;
			}
		}
	} 
	if (ct >= 100000000) ct = ct % 100000000;                
	cout << ct;
}