C :

#include<stdio.h>
int main()
{
	int a,b,c,s;
	scanf("%d%d%d",&a,&b,&c);
	s=a*0.2+b*0.3+c*0.5;
	printf("%d",s);
	return 0;
}

C++ :

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a,b,c;
    scanf("%d%d%d",&a,&b,&c);
    int x=a*0.2+b*0.3+c*0.5;//第一次强制转化
    printf("%d",x);
}

Java :

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double a = sc.nextInt();
		double b = sc.nextInt();
		double c = sc.nextInt();
		int d = 0;
		d =(int)( a * 0.2 + b * 0.3 + c * 0.5);
		System.out.println(d);
		sc.close();
	}
}

Python :

s=input().split()
x=int(s[0])
y=int(s[1])
z=int(s[2])
a=x*0.2+y*0.3+z*0.5
print(int(a))