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-csc 3.5.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace atcoder
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var buffer = Console.ReadLine().Split(' ');
            long N = int.Parse(buffer[0]);
            long A = int.Parse(buffer[1]);
            long B = int.Parse(buffer[2]);

            if (N <= A + B)
            {
                Console.WriteLine(A);
                return;
            }

            long sum = A + B;
            long cnt = N / sum * A;

            long tmp = N - N / sum * sum;
            if (tmp >= A)
                cnt += A;
            else
                cnt += tmp;

            Console.WriteLine(cnt);
        }
    }
}