#include <fstream>
#include <iostream>
using namespace std;
 
ifstream f("cifra.in");
FILE *f2=fopen("cifra.out","w");
 
int per[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};
 
int main() {
int n,i,s=0;
char t[102];
f>>n;
f.getline(t,101);
while(n>0) {
char a[102];
s=0;
f.getline(a,101);
int m=0;
for(int k=0;k<=100;k++) {
if(a[k]==0) break;
else {
i=k-1;
m*=10;
m+=a[k]-48;
m%=100;
}
}
for(int k=1;k<=100;k++) {
int tot=(i/2)+1;
if(k>m) tot--;
s+=tot*per[k-1];
}
s%=10;
fprintf(f2,"%d \n",s);
n--;
}
return 0;
}