#include<stdio.h>
int main(){
    double paymentAmount, accountBalance;
    int isActive;
    if (scanf("%lf %lf %d", &paymentAmount, &accountBalance, &isActive) !=3){
        printf("Invalid input\n");
        return 0;
    } if (paymentAmount < 0 || paymentAmount > 1000000 || accountBalance >
    1000000 || (isActive !=0 && isActive !=1)){
        printf("Invalid input\n");
        return 0;
    }
    if (isActive == 0){
        printf("Invvalid Inactive\n");
        return 0;
    }
    if (paymentAmount > accountBalance){
        printf("Insufficient Balance\n");
        return 0;
    }
    double remainingBAlance = accountBalance - paymentAmount;
    printf("%.2f\n",remainingBalance);
    return 0;
}