#include<iostream.h>
#include<stdio.h>
FILE *f=fopen("cifra.in","r"),*g=fopen("cifra.out","w");
 int main()
{
long long m,n,v[20],i,c,k,j,s=0;
v[1]=1; v[6]=6;
v[2]=4; v[7]=9; 
v[3]=9; v[8]=4;
v[4]=6; v[9]=1;
v[5]=5; v[10]=0;
fscanf(f,"%ld\n",&m);
for(i=1;i<=m;i++)
{
s=0;
 fscanf(f,"%ld\n",&n);
if(!n%10) c=((n/10)*5)%10;
else
{
c=((n/10)*5)%10;
k=n%10;
for(j=1;j<=k;j++)
s+=v[j];
c=(c+s)%10;
}
 fprintf(g,"%ld\n",c);
}
return 0;
}