Time bomb

input/code.cpp: In function 'int main()':
input/code.cpp:34:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while (start < s1.size()) {
                         ^

#include <vector>
#include <string>
#include <iostream>


using namespace std;

string s1,s2,s3,s4,s5;
int getnum(int start) {
	if (s3.substr(start, 3) == "#.#") return 0;
	if (s1.substr(start, 3) == "..#") return 1;
	if (s3.substr(start, 3) == "..#") return 7;
	if (s4.substr(start, 3) == "#..") return 2;
	if (s2.substr(start, 3) == "..#") return 3;
	if (s1.substr(start, 3) == "#.#") return 4;
	if (s2.substr(start, 3) == "#.." && s4.substr(start,3) == "..#") return 5;
	if (s2.substr(start, 3) == "#.." && s4.substr(start,3) == "#.#") return 6;
	if (s2.substr(start, 3) == "#.#" && s4.substr(start,3) == "#.#") return 8;
	return 9;
}

int main() {
	cin >>s1>>s2>>s3>>s4>>s5;
	int start=0;
	int nums = (s1.size() + 1)/4;
	long long power = 1;
	for (int i = 1; i < nums; i++) {
		power *= 10;
	}
	long long ans = 0;
	while (start < s1.size()) {
		int num = getnum(start);
//cout << num << endl;
		ans += num*power;
		power/= 10;
		start += 4;
		
	}
//cout << ans << endl;
	if (ans % 97 == 0) {
		cout << "BEER!!";
	}else {
		cout << "BOOM!";

	}

}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED