#include <bits/stdc++.h>
#define For(i,s,e) for(int i=s;i<=e;i++)
#define dFor(i,s,e) for(int i=s;i>=e;i--)
using namespace std;
int n,m,sum,s;
int a[11451][114],b[11451][114],c[11451];
int main(){
	cin>>n>>m;
	For(i,1,n){
		For(j,1,m){scanf("%d%d",&b[i][j],&a[i][j]);c[i]+=b[i][j];}
	}
	cin>>s;s++;
	For(i,1,n){
		sum=(sum+a[i][s])%20123;
		int f=a[i][s]%c[i];
		int j=s-1;
		while(f){
			j++;if(j>m)j=1;
			if(b[i][j])f--;
		}
		s=j;
	}
	cout<<sum;
}