#include <bits/stdc++.h>
#define in cin >>
#define out cout <<
#define endl '\n'
#define int long long
#define bismillah ios_base::sync_with_stdio(false); cin.tie(nullptr);
#define v vector
#define pb push_back
using namespace std;
signed main () {
int q; in q;
int tmp = 45;
while (q--) {
int l,r; in l >> r;
int sz = r - l + 1;
int ans = 0;
if (sz <= 9) {
if ((l % 9) <= (r % 9)) {
ans += (sz * ((l % 9) + (r % 9)))/2;
} else {
ans += ((sz - (r % 9)) * ((l % 9) + 9))/2;
ans += ((sz - (l % 9)) * (1 + (r % 9)))/2;
}
} else {
ans += ((9 - (l % 9) + 1) * ((l % 9) + 9))/2; sz -= (9 - (l % 9) + 1);
ans += ((r % 9) * (1 + (r % 9)))/2; sz -= (r % 9);
sz /= 9;
ans += (sz * tmp);
}
out ans << endl;
}
}
