#include <cstdio>
#include <algorithm>
using namespace std;

struct siunta {
	char r1, r2;
	int y, m, d;
	int q;
};

struct comp {
	bool operator()(const siunta& a, const siunta& b)
	{
		if (a.y != b.y)
			return a.y < b.y;
		if (a.m != b.m)
			return a.m < b.m;
		return a.d < b.d;
	}
};

int main()
{
	freopen("SAND.IN", "r", stdin);
	freopen("SAND.OUT", "w", stdout);
	int n, k;
	char v1, v2;
	scanf("%d%d %c%c", &n, &k, &v1, &v2);
	siunta S[1000];
	for (int i = 0; i < k; ++i)
		scanf(" %c%c %4d-%2d-%2d %d", &S[i].r1, &S[i].r2, &S[i].y, &S[i].m, &S[i].d, &S[i].q);
	sort(S, S+k, comp());
	int c = 0;
	for (int i = k-1; i >= 0; --i) {
		if (S[i].q <= n) {
			n -= S[i].q;
			continue;
		}
		int w = S[i].q;
		if (n) {
			w -= n;
			n = 0;
		}
		if (S[i].r1 == v1 && S[i].r2 == v2)
			c += w;
	}
	printf("%d\n", c);
	return 0;
}