#include<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
#include<cmath>
using namespace std;
int main(){
    string s;
    long long N,n,num,sum=0;
    cin >> N;
    while(N--){
        cin >> n >> s;
        num = ((n-1)/1000*12)+1;
        if((s.size()-num)>0)    sum+=(s.size()-num);
    }
    cout << sum;
    return 0;
}