#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int long long
#define maxn 303
#define mi LLONG_MIN
#define ma LLONG_MAX
#define mod 1000000007
#define pb push_back
#define S second
#define F first
map<int, int> sums;
int sumd(int x) {
if (sums.find(x) != sums.end()) {
return sums[x];
}
if (x < 10) {
sums[x] = x;
return sums[x];
}
int sum = 0;
while (x > 0) {
sum += x % 10;
x /= 10;
}
sums[x] = sumd(sum);
return sums[x];
}
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int q;
cin >> q;
map<int, int> mp;
int last = 0;
while (q--) {
int l, r;
cin >> l >> r;
l--;
if (mp.find(r) == mp.end()) {
int sum = mp[last];
for (int i = last + 1; i <= r; i++) {
sum += sumd(i);
mp[i] = sum;
}
}
last = max(last, r);
cout << mp[r] - mp[l] << endl;
}
}
