#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char *argv[])
{
	FILE *f1 = fopen("cifra.in", "r");
	FILE *f2 = fopen("cifra.out", "w");
	int T, n, r;
	int v[] = {0, 1, 5, 2, 8, 3, 9, 2, 9, 8};
	char s[101];
	fscanf(f1, "%d", &T);
	while(T--){
		fscanf(f1, "%s", s);
		n = strlen( s );
		r = (n > 2 ? s[n-2] - '0' * 7 : 0) + v[s[n-1] - '0'];
		fprintf(f2, "%d\n", r%10);
	}
	fclose(f1);
	fclose(f2);
	return 0;
}