#include<stdio.h>

unsigned int n;

int a[10][5] ={ {0,0,0,0,0},
		{1,1,1,1,1},
		{6,2,4,8,6},
		{1,3,9,7,1},
		{6,4,6,4,6},
		{5,5,5,5,5},
		{6,6,6,6,6},
		{1,7,9,3,1},
		{6,8,4,2,6},
		{1,9,1,9,1}};


unsigned int i,T,k,j,s;
char c,c1,c2,c3,c4;

int main(){

FILE *f=fopen("cifra.in","r");
fscanf(f,"%u\n",&T);
FILE *g=fopen("cifra.out","w");

for(i=1;i<=T;i++){

   char c,d,e;
   d=e='0';
   do {
     c=d;
     d=e;
//     f>>e;
     e = fgetc(f);
   } while ((e!='\n')&&(!feof(f)));

  n=(c-48)*10+(d-48);

s=0;
k=0;

  for(j=1;j<=n;j++)
  s+=a[j%10][j%4];

fprintf(g,"%u\n",s%10);

}


fclose(g);
fclose(f);
return 0;
}