#include <iostream>
#define ll long long
using namespace std;
int mov[9] = {0b1011,0b10111,0b100110,0b10111010,0b11001000,0b111010000,0b110100000};
int no,n,small = 1 << 30;
int main(int argc, char ** argv) {
	for (int i = 0; i < 9; ++i) {
		cin >> n;
		no = (no << 1) | n;
	}
	for (int i = 0,l = 0; i < (1 << 9); ++i) {
		for (int j = 0; j < 9; ++j) {
			if (i & (1 << j)) {
				no ^= mov[j];
				l++;
			}
		}
		if (no + 1 == (1 << 9) && l < small) {
			small = l;
		}
		for (int j = 0; j < 9; ++j) {
			if (i & (1 << j)) {
				no ^= mov[j];
				l--;
			}
		}

	}
	cout << small;
}