#include<cstdio>
#include<cstring>
char v[110];
int v1[21]={0,1,5,2,8,3,9,2,8,7,7,1,7,0,6,1,7,4,8,7,7};
void f()
    {int n,x,s,i;
    scanf("%s",&v);
    n=strlen(v);
    if(n==1)
        x=0;
    else
        x=v[n-2]-'0';
    s=(x*7)%10;
    if(x%2==0)
        s+=v1[v[n-1]-'0'];
    else
        s+=v1[10+v[n-1]-'0'];
    printf("%d\n",s%10);
    }
int main ()
{freopen ("cifra.in","r",stdin);
freopen ("cifra.out","w",stdout);
int t,i;
scanf("%d",&t);
for(i=1;i<=t;i++)
    f();
return 0;
}