Problem:
Score : 100 points

Problem Statement

A biscuit making machine produces B biscuits at the following moments: A seconds, 2A seconds, 3A seconds and each subsequent multiple of A seconds after activation.

Find the total number of biscuits produced within T + 0.5 seconds after activation.

Constraints

All values in input are integers.

1 \leq A, B, T \leq 20

Input

Input is given from Standard Input in the following format:

A B T

Output

Print the total number of biscuits produced within T + 0.5 seconds after activation.

Sample Input 1

3 5 7

Sample Output 1

10

Five biscuits will be produced three seconds after activation.

Another five biscuits will be produced six seconds after activation.

Thus, a total of ten biscuits will be produced within 7.5 seconds after activation.

Sample Input 2

3 2 9

Sample Output 2

6

Sample Input 3

20 20 19

Sample Output 3

0

Solution in C (Clang 3.8.0) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<stdlib.h>

int main(void){
    int i;
    int n;
    //printf(">");
    scanf("%d",&n);
    if(n<1||n>20){
        exit(0);
    }
    printf("\n");

    int v[n];
    for(i=0;i<n;i++){
        //printf(">");
        scanf("%d",&v[i]);
        if(v[i]<1||v[i]>50){
            exit(0);
        }
    }
    printf("\n");

    int c[n];
    for(i=0;i<n;i++){
        //printf(">");
        scanf("%d",&c[i]);
        if(c[i]<1||c[i]>50){
            exit(0);
        }
    }
    printf("\n");

    int x=0;
    int y=0;
    x=v[0]+v[n-1];
    y=c[0]+c[n-1];
    int ans=x-y;
    if(ans>=0){
        printf("%d\n",ans);
    }else{
        printf("0\n");
    }
    return 0;
}