#include<stdio.h>
#include<string.h>
int main()
{
	freopen("sarpe.in","r",stdin);
	freopen("sarpe.out","w",stdout);
	long int n;
	scanf("%ld",&n);
	if(n<=50000000)
	  {
		  printf("%ld",n*4);
		  return 0;
	  }  
	
	{char n[1001],v[1001];
	int i,k;
	scanf("%s",&n);
	k=strlen(n);
	for(i=0;i<k;i++)
		{
			v[i]=n[i]*4;
			if(v[i]>9)
			{
				v[i+1]=v[i+1]+v[i]/10;
				v[i]=v[i]%10;
			}
		}
		printf("%s",v);
	}
return 0;
}