# include<iostream> # include<cstring> # include<cstdio> using namespace std; int main() { int n, s = 0, ndd = 101; cin >> n; int a, b; for (int i = 1; i <= n; i++) { cin >> a >> b; if (ndd > b) { //TODO ndd = b; } s += a * ndd; } //TODO cout << s; }