#include<stdio.h>
int main()
{
    float paymentAmount,accountBalance;
    int isActive;
    if (scanf("%f", &paymentAmount) != 1||
    scanf("%f", &accountBalance) != 1
||
    scanf("%d", &isActive) != 1)
    {
        printf("Invalid input");
        return 0;
    }
    if (paymentAmount <0 || paymentAmount
> 1000000) ||
    accountBalance <0 ||
accountBalance > 1000000 ||
    (isActive != 0 && isActive !=1))
    {
        printf("Invalid input");
        return 0;
    }
    if (isActive == 0)
    {
        printf("Insufficient Balance");
        return 0;
    }
    float remainingBalance = accountBalance-paymentAmount;
    printf("%.2f",remainingBalance);
    return 0;
}