#include <bits/stdc++.h>

using i64 = long long;

int main() {
	freopen("xiaokai.in", "r", stdin);
	freopen("xiaokai.out", "w", stdout);
	std::ios::sync_with_stdio(false);
	std::cin.tie(0);
	int n;
	std::cin >> n;
	for (int i = 1; i <= n; ++ i) {
		i64 l, r, k, res = 0;
		std::cin >> l >> r;
		k = (r - l + 1) % 9, r = k + l - 1;
		for (i64 i = l; i <= r; ++ i) {
			i64 bak = i;
			while (bak) 
				res += bak % 10, bak /= 10;
		}
		std::cout << res % 9 << '\n';
	}
	return 0;
}