#include<fstream>
#include<string>
using namespace std;
int i,j,x,k;
char n[100];
char t[100];
int c(int x)
{return x%10;}
int tr(char v[100])
{int i,a=0;
for(i=0;i<strlen(v);i++)
	a=v[i]-48;
return a;}
int main()
{
ifstream f("in.txt");
ofstream g("out.txt");
f>>t;
int y=tr(t);
for(i=1;i<=y;i++)
	{f>>n;
x=tr(n);
int s=0;
for(j=1;j<=x;j++)
	{k=c(j);
switch(k)
{case 0: break;
case 1: s=s+1; break;
case 2:
if(j%4==1) s=s+2;
else if(j%4==2) s=s+4;
else if(j%4==3) s=s+8;
else s=s+6;
break;
case 3:
if(j%4==1) s=s+3;
else if(j%4==2) s=s+9;
else if(j%4==3) s=s+7;
else s=s+1;
break;
case 4:
if(j%2==1) s=s+4;
else s=s+6; 
break;
case 5: s=s+5; break;
case 6:s=s+6; break;
case 7:
if(j%4==1) s=s+7;
else if(j%4==2) s=s+9;
else if(j%4==3) s=s+3;
else s=s+1;
break;
case 8:
if(j%4==1) s=s+8;
else if(j%4==2) s=s+4;
else if(j%4==3) s=s+2;
else s=s+6;
break;
case 9:
if(j%2==1) s=s+9;
else s=s+1;}
s=s%10;}
g<<s<<endl;}}