rt

#include<bits/stdc++.h>
#define sjh0626s return
#define code 0
using namespace std;
double xi[1000010],yi[1000010],pos;
int n;
double lagrange(double arrX[],double arrY[],int n,double x)
{
	int k,i;
	double temp,y=0;
	for(int k=1;k<=n;k++){
		temp=1;
		for(int i=1;i<=n;i++){
			if(i!=k)temp*=((x-arrX[i])/(arrX[k]-arrX[i]));
		}
		y+=arrY[k]*temp,y=fmod(y,998244353);
	}
	return y;
}
int main(){
	cin>>n>>pos;
	for(int i=1;i<=n;i++){
		cin>>xi[i]>>yi[i];
	}
	cout<<lagrange(xi,yi,n,pos);
	sjh0626s code;
}