using System;

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class Program

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{

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    static void Main()

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    {

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        double euro, dollars;

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        double exchangeRate = 1.07;

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        // Input loop to ensure valid number

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        while (true)

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        {

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            if (double.TryParse(Console.ReadLine(), out euro) && euro >= 0)

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            {

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                break; // Exit the loop if the input is valid

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            }

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            else

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            {

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                // If invalid input is entered, continue prompting

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                Console.WriteLine("Please enter a valid non-negative number.");

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            }

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        }

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        dollars = euro * exchangeRate;

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        Console.WriteLine(dollars);

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    }

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}