Problem:
Score : 100 points

Problem Statement

You went shopping to buy cakes and donuts with X yen (the currency of Japan).

First, you bought one cake for A yen at a cake shop.
Then, you bought as many donuts as possible for B yen each, at a donut shop.

How much do you have left after shopping?

Constraints

1 \leq A, B \leq 1 000

A + B \leq X \leq 10 000

X, A and B are integers.

Input

Input is given from Standard Input in the following format:

X
A
B

Output

Print the amount you have left after shopping.

Sample Input 1

1234
150
100

Sample Output 1

84

You have 1234 - 150 = 1084 yen left after buying a cake.
With this amount, you can buy 10 donuts, after which you have 84 yen left.

Sample Input 2

1000
108
108

Sample Output 2

28

Sample Input 3

579
123
456

Sample Output 3

0

Sample Input 4

7477
549
593

Sample Output 4

405

Solution in C (GCC 9.2.1) (judge verdict: Runtime Error)

#include<stdio.h>

int main(){
    int A,B,C,X,ans,frag = 0;
    scanf("%d %d %d %d",A,B,C,X);
    for(int a = 0; a <= A; a++){
        ans = 500 * a;
        for(int b = 0; b <= B; b++){
            ans += 100 * b;
            for(int c = 0; c <= C; c++){
                ans += 50 * c;
                if (ans == X)
                {
                    frag++;
                }
                
            }
        }
    }
    printf("%d",frag);
}