#include<bits/stdc++.h>
using namespace std; 
int main(){
	int n,a[101];bool b[101],sum=0;cin >> n;
	for(int i = 0;i < n;i++){
		cin >> a[i] >> b[i];
		if(b[i]){
			sum += a[i];
		}else{
			sum += 10;
		}
	}
	cout << sum;
	return 0;
}