#include <bits/stdc++.h>
using namespace std;
const int N = 10010;
const int M=110;
const int mod = 20123;

int n, m;
int k;
int a[N][N];
int b[N];
int num[N][M];
int main() {
    cin >> n >> m;
    int res = 0;
    for (int i = 0;i<n;i++){
        for (int j = 0; j < m;j++){
            cin >> a[i][j] >> num[i][j];
            b[i] += a[i][j];
        }
    }
    cin >> k;
    for (int i = 0; i < n;i++){
        int t = num[i][k];
        res = (res + t) % mod;
        t %= b[i];
        if (!t) t = b[i];
        int sum = 0;
        while(sum<t){
            sum += a[i][k];
            if (sum == t) break;
            k = (k + 1) % m;
        }
    }
    cout << res << endl;
    return 0;
}