#include <bits/stdc++.h>
#define fast cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(false)
#define pb push_back
#define ppb pop_back
#define fi first
#define se second
#define sp " "
// #define endl "\n"
#define mod 1000000007
#define MAXN 200005
#define MAXM 1000006
#define inf 1e18
#define INF 0x3f
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define debug(x) for(auto& a: x) cout << a << " "
using namespace std;
typedef long long int lo;
lo n,m,p,q,k,l,a,b;
lo arr[MAXN];
lo len[MAXN];
lo cnt[MAXN];
vector<lo> v[MAXN];
string s;
vector<lo> dp;
lo color[MAXN];
lo place;
vector<lo> events;
int toDigit(lo i) {
return i%9 == 0? 9 : i%9;
}
void solve(){
lo l,r;
cin >> l >> r;
lo ans = 0;
ans += ((r-l)/9)*45;
if(r == l){
cout << r % 9 << endl;
return;
}
r = (r-l)%9 + l;
for (int i = l; i <= r; ++i)
{
ans += toDigit(i);
}
cout << ans << endl;
}
int main()
{
// cout << fixed << setprecision(12);
// freopen("feast.in","r",stdin);
// freopen("feast.out","w",stdout);
// fast;
int t = 1;
cin >> t;
while(t--)
{
solve();
}
}
// ans += ((r-l)/9)*45;
// r = ((r-l)%9)+l;
// for(lo i = l;i <= r; i++) {
// ans += toDigit(i);
// }
// cout << ans << endl;
