#include <stdio.h>
#include<string.h>
void transform(char *s,int *v){
	int i,j;
	v[0]=strlen(s);
	for(i=1,j=v[0];i<=strlen(s) ;i++,j--)
		v[j]=s[i-1]-'0';
}
int main () {
	int v[1001]={0},x,u=1,suma=0,i,k,expon,m,t,l,w;
	char s[1001];
	FILE *in=fopen("cifra.in","r");
	FILE *out=fopen("cifra.out","w");
		fscanf(in,"%d\n",&t);
		for(w=0;w<t;w++){
			suma=0;
		fscanf(in,"%s",&s);
		transform(s,v);
		x=v[2]*10+v[1];
		for(i=1;i<=x;i++){
			expon=i%4;
			if(i%4==0)
				expon=4;
			u=1;
			m=i%10;
		for(k=0;k<expon;k++)
			u=(u*m)%10;
		suma=(suma+u)%10;
				}
		fprintf(out,"%d\n",suma);
		} 
	fclose(out);
	return 0;
}