#include "bits/stdc++.h"
#define endl '\n'
#define pb push_back
#define all(a) (a).begin(), (a).end()
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<ll> vl;
typedef vector<int> vi;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<int>::iterator vit;
typedef set<int> si;
typedef map<int, int> mii;
void solve() {
ll l,r;
cin >> l >> r;
ll la= (l-1)%9+1;
ll ra= (r-1)%9+1;
ll kat = 9*5;
ll ans=0;
int li = l,ri = r;
for (int i = la; i <9; i++){
ans+=i;
li++;
}
ans+=ra;
for (int i = ra ; i<9;i++){
ans-=i;
ri++;
}
if (ri==li){
cout << ans <<endl;
return;
}
ans+=5*(ri-li);
cout << ans << endl;
}
int main() {
std::ios::sync_with_stdio(false);
cin.tie(nullptr);
unsigned long long ct = 1;
cin >> ct;
while (ct--)
solve();
}
