#include<stdio.h>
int main()
{
    int paymentAmount,accountBalance,isActive;
    
    if(scanf("%d %d %d",&paymentAmount,&accountBalance,&isActive) !=3){
        printf("Invalid input");
        return 0;
    }
    
    if(isActive == 0){
        printf("Insufficient Balance");
    }
    else{
        float remainingBlance=accountBalance -paymentAmount;
        printf("%.2f",remainingBalance);
    }
    
    
    returnj 0;
    
    }