#include<stdio.h>
FILE *f1,*f2;
char c;
long a,b,i,j,t,n,nr[4],rest1[32]={0,1,5,12,18,23,29,32,38,47,47,48,54,57,63,68,74,81,85,94},rest2[8]={0,4,8,2,6};
int main(){
	f1=fopen("cifra.in","r");
	f2=fopen("cifra.out","w");
	fscanf(f1,"%ld",&t);
	fscanf(f1,"%c",&c);
	for(i=1;i<=t;i++){
		fscanf(f1,"%c",&c);
		nr[1]=0;
		nr[2]=0;
		while(c!='\n'&&!feof(f1)){
			nr[1]=nr[2];
			nr[2]=c-'0';
			fscanf(f1,"%c",&c);
		}
		n=nr[1]*10+nr[2];
		fprintf(f2,"%ld\n",(rest2[n/20]+rest1[n%20])%10);
		
	}
	return 0;
}
/*
0  0
1  1
2  4(4k+2) 6(4k+2+10=4p) etc
3  7 3 etc
4  6
5  5
6  6
7  3 7 etc
8  6 4 etc
9  9
serii 1-20=94
94 4 8 2 6 0 etc
*/