#include<cstdio>
#include<cstring>
using namespace std;
char s[110];
int v[110];
int ridic_la_putere(int baza){
    int rez=1,exp=baza;
    while(exp!=0)
        if(exp%2==1){
            rez=rez*baza;
            exp--;
            rez%=10;
        }
        else{
            baza=baza*baza;
            baza%=10;
            exp/=2;
        }
    return rez;
}
int main(){
    freopen("cifra.in","r",stdin);
    freopen("cifra.out","w",stdout);
    int t,q,l;
    scanf("%d\n",&t);
    for(q=1;q<=100;q++)
        v[q]=(v[q-1]+ridic_la_putere(q))%10;
    for(q=1;q<=t;q++){
        scanf("%s",&s);
        l=strlen(s);
        if(l==1){
            printf("%d\n",v[s[0]-'0']);
            continue;
        }
        printf("%d\n",v[s[l-1]-'0'+10*(s[l-2]-'0')]);
    }
    return 0;
}