public class ConversionTool {


    public static void main(String[] args){
        
    }
    
    public static float ErrorCheck(float unit){
        if(unit < 0){
            return (float)0.0;
        }
        else 
            return unit;
    }

    public static float CentimetersToInches(float centimeters){
        centimeters = ErrorCheck(centimeters);
        return centimeters * (float)0.3937;
    }

    public static float InchesToCentimeters(float inches){
        inches = ErrorCheck(inches);
        return inches * (float)2.54;
    }

    public static float FeetToMeters(float feet){
        feet = ErrorCheck(feet);
        return feet * (float)0.3048;
    }

    public static float MetersToFeet(float meters){
        meters= ErrorCheck(meters);
        return meters * (float)3.28084;
    }

    public static float CelsiusToFahrenheit(float celsius){
        celsius = ErrorCheck(celsius);
        return (celsius * (float)9/5) + 32;
    }

    public static float FahrenheitToCelsius(float fahrenheit){
        fahrenheit = ErrorCheck(fahrenheit);
        return (fahrenheit - 32) * (float)5/9;
    }

    public static float MphToKph(float mph){
        mph = ErrorCheck(mph);
        return mph * (float)1.60934;
    }

    public static float KphToMph(float kph){
        kph = ErrorCheck(kph);
        return kph * (float)0.621371;
    }
}