#include<math.h>


#include<stdio.h>
int j,ac,n,i,s,uc,uc1,t;

int main()
{
FILE *f=fopen("cifra.in","r"),*g=fopen("cifra.out","w");
fscanf(f,"%d",&t);

for(j=1; j<=t; j++){s=0;

fscanf(f,"%d",&n);
for(i=1; i<=n; i++)
{
uc1=0;
uc=i%10;
if(uc==0 || uc==1 || uc==5 || uc==6 )uc1=uc;
if(uc==4 || uc==9 ) if(uc%2==0) uc1=(uc*uc)%10; else uc1=uc;
if(uc==2 || uc==3 || uc==7 || uc==8)
{ac=pow(uc,(i%4)+4);
uc1=ac%10;}

s=s+uc1;
}
s=s%10;
fprintf(g,"%d\n",s);
}


return 0;
}