#include <iostream>
using namespace std;
#define endl '\n'
#define ll long long
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
ll T, l, r, res, x;
cin >> T;
while (T--)
{
cin >> l >> r;
if (r - l + 1 <= 20)
{
res = 0;
for (ll i = l; i <= r; i++)
{
res += i % 9;
if (i % 9 == 0) res += 9;
}
cout << res << endl;
continue;
}
res = 0;
for (ll i = 1; i <= r % 9; i++)
res += i;
x = (l % 9);
if ((!x)) x = 9;
for (ll i = x; i <= 9; i++)
res += i;
r -= r % 9;
l += 9 - x + 1;
if (l <= r) res += (r - l + 1) * 45 / 9;
cout << res << endl;
}
return 0;
}
