#include<stdio.h>
int t,s,i,x,aux,y,c,b,j,n; 

int main(){

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

FILE *f=fopen("cifra.in","r");
FILE *g=fopen("cifra.out","w");

fscanf(f,"%d",&t);

s=0;
for(i=1;i<=9;i++){
s=s+v[i];
}
s=s%10;


  for(i=1;i<=t;i++){
  fscanf(f,"%d",&x);
  aux=x;

      //while(aux!=0){
      //c++;
      //aux=aux/10;
      //}
  y=x/10;
  c=x%10;

  n=y*s+v[c];
     fprintf(g,"%d\n",n%10);

  }


fclose(f);
fclose(g);

return 0;
}