这份代码怎么假了

#include <bits/stdc++.h>
using namespace std;
const int N = 85,M = 20005,INF = 2139062143;
int n,x,y,a[N],b[N],f[N][M];
int main()
{
	scanf("%d%d%d",&n,&x,&y);
	for(int i = 1;i <= n;i++) scanf("%d%d",&a[i],&b[i]);
	memset(f,127,sizeof(f));
	f[0][0] = 0;
	for(int i = 1;i <= n;i++)
		for(int j = i;j >= 1;j--)
			for(int k = a[i];k <= a[i] + x;k++)
				if(f[j - 1][k - a[i]] <= y)
					f[j][k] = min(f[j][k],f[j - 1][k - a[i]] + b[i]);
	for(int j = n;j >= 1;j--)
		for(int k = 1;k <= 20000;k++)
			if(f[j][k] != INF)
			{
				printf("%d\n",j);
				return 0;
			}
}