#include <stdio.h>
int main() {
    int payementAmount, accountBalance, isActive;
    if (scanf("%d %d %d", &paymentAmount, &accountBalance, &isActive) != 3) {
        printf("Invalid input\n");
        return 0;
    }
    if (isActive == 0) {
        printf("account inactive\n");
    }
    else if (paymentAmount > accountBalance) {
        printf("insufficiant Balance\n");
    }
    else {
        foat remaining = (float)(accountBalance - paymentAmount);
        printf("%.2f\n",remaining);
    }
    return 0;
}