from std import console.*
from std import convert.*

 //import std.console.*
 //import std.convert.*

func getOrThrow(p: ?String): String{
    match (p) {
        case Some(x) => x
        case None => "none"
    }
}

func getInput():String{
    var input=Console.stdIn.readln()
    var rr = input.getOrThrow()
    let input_to_strig: Option<String> = input
    var input_to_strig_to :String=getOrThrow(input_to_strig)
   
    return input_to_strig_to
    }

func getCelsius(fahrenheit_string :String):Int64{
    var fahrenheit : Int64 = Int64.parse(fahrenheit_string)
    var celsius: Int64 = 5*(fahrenheit-32)/9
    return celsius
}

main(){
    var fahrenheit:String =getInput()
    if(!fahrenheit.isEmpty()){
        var celsius:Int64=getCelsius(fahrenheit)
        println("Celsius = ${celsius}")
    }

    return 0
}