#include <bits/stdc++.h>   using namespace std;   const double eps = 1e-8;   const int MAXN = 1e2 + 5;   const long long MOD = 1e9 + 7;   int a[1005][3000];   int main() {     int n, s, d;     int maxx = 0;     cin >> n;     for (int i = 0; i < n; i++) {       cin >> s >> d;       for (int j = s; j <= 100000000; j += d) {         if (j > maxx) {           maxx = j;           break;         }       }     }     cout << maxx << endl;     return 0;   }   