#include <stdio.h>

int main()
{
	int t,n,j=0,i,x;
	char v[30001][101];
	freopen("cifra.in","r",stdin);
	freopen("cifra.out","w",stdout);
	scanf("%d",&n);
	for(i=1;i<=n;i++){
		while(scanf("%d",&v[i][j])!=EOF){
			j++;
		}
		if(j==0){
			x=v[i][j]*v[i][j]%10;
			printf("%d",x);
		}else{
			x=(v[i][j-1]*9+v[i][j]*v[i][j]%10)%10;
			printf("%d",x);
		}
	}
	return 0;
}