#include<iostream.h>
#include<fstream.h>
int main()
{int T,r,o,t;
long N,x,e;
fstream f("cifra.in",ios::in),g("cifra.out",ios::out);
f>>T>>N;
for (o=0;o<T;o++)
{e=0;
for (x=1;x<=N;x++)
{r=1;	
for (t=0;t<x;t++)
	r=r*x;
e=e+r;
}
g<<(e%10)<<endl;
f>>N;
}
}