#include<stdio.h>
#include<string.h>
char s[102];
int t,m,n,v[101],i;
int put(int n)
{int x=n,y=1,t=n;
while(t)
       {if(t&1)
              y=(x*y)%10;
       t/=2,x=(x*x)%10;}
return y;}

int main()
{freopen("cifra.in","r",stdin);
freopen("cifra.out","w",stdout);
scanf("%d\n",&t);
for(i=1;i<100;i++)
       v[i]=(v[i-1]+put(i))%10;
while(t--)
       {scanf("%s\n",s);
       m=strlen(s);
       if(m>1)
              n=(s[m-2]-'0')*10+(s[m-1]-'0');
       else
              n=s[m-1]-'0';
       printf("%d\n",v[n]);}
return 0;
}