Problem:
Score : 200 points

Problem Statement

Takahashi has many red balls and blue balls. Now, he will place them in a row.

Initially, there is no ball placed.

Takahashi, who is very patient, will do the following operation 10^{100} times:

Place A blue balls at the end of the row of balls already placed. Then, place B red balls at the end of the row.

How many blue balls will be there among the first N balls in the row of balls made this way?

Constraints

1 \leq N \leq 10^{18}

A, B \geq 0

0 < A + B \leq 10^{18}

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N A B

Output

Print the number of blue balls that will be there among the first N balls in the row of balls.

Sample Input 1

8 3 4

Sample Output 1

4

Let b denote a blue ball, and r denote a red ball. The first eight balls in the row will be bbbrrrrb, among which there are four blue balls.

Sample Input 2

8 0 4

Sample Output 2

0

He placed only red balls from the beginning.

Sample Input 3

6 2 4

Sample Output 3

2

Among bbrrrr, there are two blue balls.

Solution in JavaScript (node.js v5.12) (judge verdict: Runtime Error)

import java.math.BigInteger;
import java.util.Scanner;
import java.util.*;
import java.io.*;
public class Main {
    public static void main(String [] args){
        Scanner cin = new Scanner(System.in);
          
                BigInteger a,n,c,d;
                BigInteger b,e;
                n=cin.nextBigInteger();
                a=cin.nextBigInteger();//输入大数
                b=cin.nextBigInteger();
                d=a.add(b);
				c=n.divide(d);
                c=c.multiply(a);
                e=n.mod(d);
                if(e.compareTo(a)==-1) c.add(e); 
                else c.add(a);
                
            
            System.out.println(c);//println会自动换行，不想换行时用print
           
        
    }
}