#include <stdio.h>
#define fr(i,a,b) for(int i=a;i<b;++i)
#define ll long long
int a[10]={0,1,5,2,8,3,9,2,8,7};
int b[10]={0,1,7,0,6,1,7,4,8,7};

int main(){
    freopen("cifra.in","r",stdin);
    freopen("cifra.out","w",stdout);
    int t;
    scanf("%i\n",&t);
    fr(i,0,t){
        char c1,c2,c3;c1=c2=c3='0';
        while(c3!='\n'){
            c1=c2;c2=c3;
            scanf("%c",&c3);
            }
        int s=(c1-'0')*7;
        if((c1-'0')%2) s+=b[c2-'0'];
        else s+=a[c2-'0'];
        s=s%10;
        printf("%i\n",s);
        }
    return 0;
    }