#include <bits/stdc++.h>
#define int long long
#define N 200005
using namespace std;
int f(int x){
int s=0;
while(x){
s+=x%10;
x/=10;
}
if(s>=10)return f(s);
else return s;
}
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int q;
cin >> q;
while(q--){
int l,r;
cin >> l >> r;
int arr[]={0,1,2,3,4,5,6,7,8,9};
for(int i=1;i<=9;i++)arr[i]+=arr[i-1];
int x=f(l);
int y=f(r);
int k=(r-l+1)-(9-x+1)-y;
int ans=45*(k/9)+arr[9]-arr[x-1]+arr[y]-arr[0];
cout << ans << "\n";
}
return 0;
}
/*
*/
