#include <iostream>
#define F first
#define S second
#define ll long long
#define pb push_back
#define endl '\n'
using namespace std;
const int MOD = 1e9 + 7;
const int N = 510;
string e(ll x) {
string s;
while(x) {
s += char('0' + x % 10);
x /= 10;
}
return s;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int T;
cin >> T;
while(T--) {
ll a, b;
cin >> a >> b;
ll sum = 0;
for (ll i = a; i <= b; ++i) {
ll x = sum;
string s = e(i);
for (char c: s) {
sum += (c - '0');
}
while (sum > x + 9) {
s = e(sum - x);
sum = x;
for (char c: s) {
sum += (c - '0');
}
}
}
cout << sum << endl;
}
}
