#include<stdio.h>
#define N 301

int n,x1,x2,x[N],k,sum;

int main() {
	int i;
	freopen("cd.in","r",stdin);
	freopen("cd.out","w",stdout);
	scanf("%d%d",&n,&sum); sum/=n;
	for(i=1;i<=n;++i) {
		scanf("%d%d",&x1,&x2);
		x[i]-=x1; x[x2]+=x1;
	}
	for(i=1;i<=n;++i)
		x[i]=sum-x[i];
	k=1;
	for(i=1;i<=n;++i) {
		k*=(x[i]-1);
		k%=9901;
	}
	printf("%d",k);
	return 0;
}