#include<stdio.h>
int main() 
{
    int n, id, type;
    char name[100];
    double sal, total = 0;
    scanf("%d", &n);
    if (n < 0) {
        printf("-1");
        return 0;
    }
    while (n--) {
        scanf("%s %d %d", name, &id, &type);
        scanf("%.1f", &sal);
        total += sal;
    }
    printf("%.2f", total);
    return 0;
}