#include<fstream>

char ch;
short int cf[1010],p=1010,solved[1010];

int main()
{
    std::ifstream fin("sarpe.in");
    std::ofstream fout("sarpe.out");

    fin>>ch;
    while(!fin.eof())
    {
        p--;
        cf[p]=ch-'0';
        fin>>ch;
    }
    solved[p-1]=-1;
    /*for(int i=1;i<=p;i++)
    {
        fout<<cf[i];
    }*/
    for(int i=1009;i>=p;i--)
    {
        solved[i]+=cf[i]*4;
        if(solved[i]>9)
        {
            solved[i-1]+=solved[i]%10;
            solved[i]/=10;
        }
    }
    if(solved[p-1]!=-1)
    {
        solved[p-1]++;
        p--;
    }
    for(int i=1009;i>=p;i--)
    {
        fout<<solved[i];
    }
}