#include <stdio.h>

int main() {
	int t, s[1000], tmp, r[1000], i, j, k, l;

	scanf("%d", &t);
	getchar();
	for (i = 0; i < t; i++) {
		for (j = 0; (s[j] = getchar()) != '\n'; j++) {
			s[j] -= '0';
		}
		for (l = 0; l < j - 1; l++) {
			for (k = 0; k < j; k++) {
				tmp = s[k] + s[k + 1];
				if (tmp >= 10) tmp -= 9;
				s[k] = tmp;
			}
		}
		r[i] = s[0];
	}

	for (i = 0; i < t; i++) printf("%d\n", r[i]);
	return 0;
}