#include <stdio.h>
#include <string.h>
int a, b, T,i,j, l, S1, S2, nr;
char x[101];
int v[11]={0, 1, 4, 7, 6, 5, 6, 3, 6, 9};

void calcul()
{

FILE*f=fopen("cifra.in", "r");
FILE*g=fopen("cifra.out", "w");
fscanf(f, "%d\n", &T); 
for(i=1;i<=T;i++) 
{
	for(j=0;j<=100;j++) x[j]=0;
	fgets(x, 100, f); 
	l=strlen(x); 
	//l--;


	if(l>1) a=x[l-2]-'0';
		else a=0;
	b=x[l-1]-'0';
	S1=0;
	for(j=0;j<=b;j++) S1+=v[j];
	S2=(7*a)%10;
	nr=(S1+S2)%10;

	fprintf(g,"%d\n", nr);

}
fclose(f);
fclose(g);
}




int main()
{
calcul();
return 0;
}