/*
* * author: attacker
* * created: 11.01.2026 11:28:45
*/
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "algo/debug.h"
#else
#define debug(...) 42
#endif
#define mt_rng mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int q;
cin >> q;
auto Cost = [&](int64_t num) {
int64_t x = num;
while (x >= 10) {
int64_t s = 0;
while (x > 0) {
s += (x % 10);
x /= 10;
}
x = s;
}
return x;
};
while (q--) {
int64_t low, high;
cin >> low >> high;
int64_t sum = 0;
int64_t cnt = high - low + 1;
int64_t val = Cost(low);
while (val != 1 && cnt > 0) {
sum += val;
val++;
cnt--;
if (val == 10) val = 1;
}
if (cnt >= 9) {
sum += (cnt / 9) * 45;
cnt = cnt % 9;
}
while (cnt--) {
if (val == 10) {
val = 1;
sum += val;
} else {
sum += val;
}
++val;
}
cout << sum << '\n';
}
return 0;
}
