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;
using System.Linq;
using System.Collections.Generic;

class Program
{
	static void Main(string[] args)
	{
		//文字列を読み込む
		string[] S = Console.ReadLine().Split(' ');
		long N = long.Parse(S[0]);
		long A = long.Parse(S[1]);
		long B = long.Parse(S[2]);

		//全体を一セットで割った余り
		long div = N / (A+B);

		//答えを入れる変数
		long answer = div * A;

		//余り
		long resid = N % (A+B);

		//余りが0ではない場合
		if(resid != 0){
				//余りがA以上の場合
				if(resid >= A){
						answer += A;
				}
				//そうでない場合
				else{
						answer += resid;
				}
		}

		Console.WriteLine(answer);

	}
}