#include<stdio.h>
#include<iostream.h>
#include<string.h>

int n[10003];

void citire()
{
  char s[10003];
  freopen("sarpe.in","r",stdin);
  scanf("%s",&s);
  int i, l;
  l=strlen(s);
  for (i=0; i<l; i++)
    n[l-i]=s[i]-'0';
  n[0]=strlen(s);
}


void inmultire(int A[], int B)
{
      int i, t = 0;
      for (i = 1; i <= A[0] || t; i++, t /= 10)
	      A[i] = (t += A[i] * B) % 10;
      A[0] = i - 1;
}

void afis()
{
  freopen("sarpe.out","w",stdout);
  for (int i=n[0]; i>=1; i--)
    printf("%d",n[i]);
}

int main()
{
  citire();
  inmultire(n,4);
  afis();
  return 0;
}