package main

import . "fmt"
import . "math/big"

func main() {
	var t int
	Scan(&t)
	a := new(Int)
	ten := NewInt(10)
	for ; t>0; t-- {
		var s string
		Scan(&s)
		var ans int
		for i := range s {
			x := int(a.Binomial(int64(len(s)), int64(i+1)).Mod(a, ten).Int64())
			var y int
			Sscan(s[i:i+1], &y)
			ans = (ans + x*y)%10
		}
		Println(ans)
	}
}