#include <bits/stdc++.h>
#define int long long
#define bismillah ios_base::sync_with_stdio(false);
using namespace std;
int digit(int x){
int ret = 0;
while(x > 0){
ret += x % 10;
x /= 10;
}
if(ret > 10) return digit(ret);
return ret;
}
signed main() {
bismillah;
int q;
cin >> q;
while(q--){
int L, R;
cin >> L >> R;
int sel = R - L + 1;
int ans = 0;
for(int i = digit(L); i <= 9; i++){
ans += i;
sel--;
}
for(int i = digit(R); i >= 1; i--){
ans += i;
sel--;
}
ans += (sel / 9) * 45;
cout << ans <<endl;
}
return 0;
}
