#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))
    {
        printf("Invalid input");
        return 0;
    }
    if (isActive == 0)
    {
        printf("Insufficient Balance");
        return 0;
    }
    float remainingBalance = accountBalance-paymentAmount;
    printf("%.2f",remainingBalance);
    return 0;
}