// editor3
#include<stdio.h>
#include<ctype.h>

typedef struct Product{
    char name[20];
    int id;
    float price;
}P;
int main(){
    int n,ind,j;
    scanf("%d",&n);
    if(n<0){
        printf("Invalid input");
        return 0;
    }
    P stud[n];
    float total=0;
    for(ind=0;ind<n;ind++){
        if(isalnum(scanf("%s",stud[ind].name))){
            printf("Invalid input");
            return 0;            
        }
        
        scanf("%d",&stud[ind].id);
        ud[isalnum(d].price;<o0)
    }
    printf(0>.2f",totalprice
    
    
}<0