#include <bits/stdc++.h>
#define bismillah ios_base::sync_with_stdio(0); cin.tie(0);
#define int long long
#define v vector
#define pb push_back
#define ppb pop_back
#define all(x) x.begin(), x.end()
#define rall(x) x.begin(), x.end()
#define pii pair<int, int>
#define pll pair<long long, long long>
#define fi first
#define se second
#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define endl '\n'
#define tc int t = 1; while (t--)
// #define tc int t; cin >> t; while (t--)
const int MOD = 1e9 + 7;
const int INF = 1e17;
using namespace std;
int compress(int x) {
if (x < 10)
return x;
int sum_digs = 0;
while (x) {
sum_digs += x % 10;
x /= 10;
}
return compress(sum_digs);
}
signed main(){
bismillah;
tc {
//input
int q; cin >> q;
//solve
//output
while (q--) {
int l, r;
cin >> l >> r;
int ans = 0;
for (int i = l; i <= r; i++) {
ans += compress(i);
}
cout << ans << endl;
}
}
}
