求助，为什么全部WA

#include <iostream>
using namespace std;

struct Student
{
	long long code;
	int score;
};

int main()
{
	int N, M;
	cin >> N >> M;
	Student student[5001];
	for (int i = 0; i < N; i++)
	{
		student[i].score = 0;
		cin >> student[i].code;
	}
	for (int k = 0; k < M; k++)
	{
		long long P;
		int S;
		cin >> P >> S;
		for (int i = 0; i < N; i++)
		{
			if (student[i].code == P)
			{
				student[i].score = S;
				break;
			}
		}
	}
	int fail = 0;
	int lack = 0;
	for (int i = 0; i < N; i++)
	{
		if (student[i].score < 60)
		{
			fail++;
			if (student[i].score == 0)
			{
				lack++;
			}
		}
	}
	cout << lack << endl;
	cout << fail << endl;
	return 0;
}