C :

#include<stdio.h>
int main()
{
	int a,b,c;
	scanf("%d%d%d",&a,&b,&c);
	printf("%d",a-b*c);
	return 0;
}

C++ :

#include<iostream>
#include <iomanip>
using namespace std;
int main(){
	int n,a,x;
	cin>>n>>a>>x;
	cout<<n-a*x;
} 

Java :

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner (System.in);
		int n = sc.nextInt();
		int a = sc.nextInt();
		int x = sc.nextInt();
		System.out.print(qingWa(n,a,x));
		
	}
	public static int qingWa(int a,int b,int c) {
		int n = a - b * c;
		
		return n;
	
	}

}

Python :

#!/usr/bin/python3
a,b,c=map(int,input().split())
print(a-b*c)