Gondola Groups

#include <iostream>

using namespace std;

const int N = 1e5 + 5;

int am[N];

int main() {
	int n;
	cin >> n;

	for(int i = 1; i <= 4*n; ++i) {
		int a;
		cin >> a;
		--a;
		am[a/4] += 1;
		if(am[a/4] == 4) {
			cout << a/4 + 1 << "\n";
			return 0;
		}
	}	
}

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