#include <stdlib.h>
#include <string.h>
#include <stdio.h>
int main ()
{char line[110];
 unsigned t,i,j,s;
 int nr;
 int r[10]={1,1,4,4,2,1,1,4,4,2};
 int m[10][4]={{0,0},{1,1},{6,2,4,8},{1,3,9,7},{6,4},{5,5},{6,6},{1,7,9,3},{6,8,4,2},{1,9}};
 FILE *f,*ff;
 f=fopen("cifra.in","r");
 ff=fopen("cifra.out","w");
 fscanf(f,"%u\n",&t);
 for (i=1;i<=t;i++)
 {s=0;
  fgets(line,110,f);
  if(strlen(line)>3){nr=atoi(line+strlen(line)-3);}
  else nr=atoi(line);
  for (j=1;j<=nr;j++)
  {s+=m[j%10][(j%100)%r[j%10]];
   if(s>30000){s=s%10;}
  }

  fprintf(ff,"%d\n",s%10);
 }
 fclose(ff);
  return 0;
}