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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
class AtCoder
{
    static void Main(string[] args)
    {
      	var str = Console.ReadLine().Split(' ');
      	var n = ulong.Parse(str[0]);
      	var a = ulong.Parse(str[1]);
      	var b = ulong.Parse(str[2]);
       
       var x = (n/(a+b));
      var y = x*a;
       var sub = n - (a+b)*x;
      if( sub > a ){
        Console.WriteLine((y+a).ToString());
      }
      else{
        Console.WriteLine((y+sub).ToString());
      }
    }
}