#include <fstream>
#include <iostream>
#include <cstring>

using namespace std;

int a[10][10],i,j,s[101],s1,t,nr;
char n[101];

int main()
{ifstream f1("cifra.in");
ofstream f2("cifra.out");

a[0][0]=1;a[0][1]=0;
for (i=1;i<=9;i++)
{a[i][0]=1;j=1;a[i][j]=i;
while (i*a[i][j]%10!=a[i][1])
{j++;a[i][j]=i*a[i][j-1]%10;a[i][0]++;
}
}
s1=0;
for (i=1;i<=100;i++)
    {if (i%a[i%10][0]==0) s1=(s1+a[i%10][a[i%10][0]])%10; else s1=(s1+a[i%10][i%a[i%10][0]])%10;s[i]=s1%10;}

f1>>t;
for (i=1;i<=t;i++)
{f1>>n;
if (strlen(n)==1) nr=n[strlen(n)-1]-'0';else
nr=(n[strlen(n)-2]-'0')*10+(n[strlen(n)-1]-'0');
if (nr==0) f2<<s[100]<<'\n';
else f2<<s[nr]<<'\n';
}
f1.close();f2.close();
return 0;
}