#include<fstream.h>
#include<string.h>
int v[100]=
{1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0,1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0,1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0,1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0,1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0};
char sir[101];
int sumx()
{int val,cif,i,l;
l=strlen(sir);
if(l>=2) val=(sir[1]-'0')*10+(sir[0]-'0');
 else val=sir[0]-'0';
cif=0;
for(i=0;i<val;i++)
 cif=cif+v[i];
return (cif%10);
}
int main()
{ifstream f("cifra.in");
ofstream g("cifra.out");
int i,t;
f>>t;f.get();
for(i=1;i<=t;i++)
 {f.getline(sir,101,'\n');
  g<<sumx()<<'\n';
 }
f.close();
g.close();
return 0;
}