// author: sofwant || a6cenna
// created at 27/03/2025
// suffering leaves suffering leaves.
#include <bits/stdc++.h>
using namespace std;
#define suffering_leaves_suffering_leaves ios::sync_with_stdio(false); cin.tie(nullptr);
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define fs first
#define sc second
#define pb push_back
void solve() {
ll l,r;cin>>l>>r;
// pake deret aritmatika
ll a=l%9;
int n=r-l+1;
int ans=n/9*45;
if(n%9!=0) {
ans+=((n%9)*(a+(r%9)))/2;
}
cout << ans;
}
int main() {
suffering_leaves_suffering_leaves
int t;
cin >> t;
while(t--) {
solve();
}
}
