C :

#include<stdio.h>
int main(){
int a;
double x,y;
scanf("%lf %d %lf",&x,&a,&y);
printf("%.6lf\n",x+a%3*(int)(x+y)%2/4);
return 0;
}

C++ :

#include <stdio.h>
int main() {
	double x, y, ans;
	int a;
	scanf("%lf %d %lf", &x, &a, &y);
	ans = x + a % 3 * (int)(x + y) % 2 / 4;
	printf("%.6f\n", ans);
	return 0;
}

Java :

import java.util.*;
public class Main {
	public static void main(String args[]) {
		Scanner cin = new Scanner(System.in);
		double x,y;
		int a;
		x=cin.nextDouble();
		a=cin.nextInt();
		y=cin.nextDouble();
		double r = x+a%3*(int)(x+y)%2/4;
		System.out.printf("%.6f",r);
	}
}