import java.io.*;

public class Ik2_3 {

public static void main ( String args[] )

throws IOException {

// 変数宣言

double value_double = 0;

// キーボード入力用のおまじない

BufferedReader br

= new BufferedReader( new InputStreamReader(System.in) );

System.out.println( "実数を入力してください" );

value_double = Double.parseDouble( br.readLine() );

value_double = value_double * 1.4;

System.out.println( value_double );

}

}