#include <iostream>
#include <fstream>
long long s;
int n,i;
using namespace std;
ifstream fin("cifra.in");
ofstream fout("cifra.out");
int main()
{
fin>>n;
s=0;
for (i=1;i<=n;i++) {
    if (i%10==1) s=s+1;
if (i%10==2) {if (i%4==1) s=s+2;
if (i%4==2) s=s+4;
if (i%4==3) s=s+8;
if (i%4==0) s=s+6;
}
if (i%10==3) {if (i%4==1) s=s+3;
if (i%4==2) s=s+9;
if (i%4==3) s=s+7;
if (i%4==0) s=s+1;
}
if (i%10==4) s=s+6;
if (i%10==5) s=s+5;
if (i%10==6) s=s+6;
if (i%10==7) {if (i%4==1) s=s+7;
if (i%4==2) s=s+9;
if (i%4==3) s=s+3;
if (i%4==0) s=s+1;
}
if (i%10==8) {if (i%4==1) s=s+8;
if (i%4==2) s=s+4;
if (i%4==3) s=s+2;
if (i%4==0) s=s+6;
}
if (i%10==9) s=s+9;
}
fout<<s%10;



    return 0;
}