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


int main() {

    int uc[10] = {7,1,5,2,8,3,9,2,8,7};

    int     T,i;
    char    nr[101];

    freopen("cifra.in","r",stdin);
    freopen("cifra.out","w",stdout);

    scanf("%d\n",&T);

    int last,prev;
    int len;

    for ( i = 0; i < T; i++) {
        scanf("%s",nr);
        len = strlen(nr);
        last = nr[len-1] - '0';
        if (len>1) prev = nr[len-2] - '0';
            else prev = 0;

        printf("%d\n",(prev*uc[0]+uc[last])%10);
    }
    return 0;
}