#include <bits/stdc++.h>
struct Amplifier{
    long long m, c;
    bool operator<(Amplifier &o){
        return o.m * c + o.c > m * o.c + c;
    }
};
// cb (ma - 1)
int main() {
    std::ios_base::sync_with_stdio(false); std::cin.tie(nullptr);
    int n;
    std::cin >> n;
    Amplifier a[n];
    for(int i=0; i<n; ++i)
        std::cin >> a[i].m >> a[i].c;
    std::sort(a, a+n);
    long long ans{1};
    for(auto &[m, c] : a)
        ans = ans * m + c;
    std::cout << ans << '\n';
}

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

MgozIDUKNCA3Cg==

2
3 5
4 7