Problem:
Score : 100 points

Problem Statement

Snuke has a favorite restaurant.

The price of any meal served at the restaurant is 800 yen (the currency of Japan), and each time a customer orders 15 meals, the restaurant pays 200 yen back to the customer.

So far, Snuke has ordered N meals at the restaurant.
Let the amount of money Snuke has paid to the restaurant be x yen, and let the amount of money the restaurant has paid back to Snuke be y yen.
Find x-y.

Constraints

1 ≤ N ≤ 100

Input

The input is given from Standard Input in the following format:

N

Output

Print the answer.

Sample Input 1

20

Sample Output 1

15800

So far, Snuke has paid 16000 yen, and the restaurant has paid back 200 yen. Thus, the answer is 15800.

Sample Input 2

60

Sample Output 2

47200

Snuke has paid 48000 yen for 60 meals, and the restaurant has paid back 800 yen.

Solution in C (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
//絶対値
long long int change_plus(long long int a) {
	if (a < 0) { return -a; }
	if (a >= 0) { return a; }
}
//大小比較(大)
long long int big(long long int a, long long int b) {
	if (a >= b) {
		return a;
	}
	else {
		return b;
	}
}

//大小比較(小)
long long int small(long long int a, long long int b) {
	if (a >= b) {
		return b;
	}
	else {
		return a;
	}
}

int main() {
	long long int n, m, k = 0;
	char str[15],str2[15],str3[15];
	scanf("%lld",&n);
	printf("%lld", n * 800 - (n / 15) * 200);
}