#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define str string
#define pb push_back
#define pf push_front
#define in insert
#define all(v) v.begin(),v.end()
const int sz=1000000,INF=1000000000;
using namespace std;
ll f(ll num)
{
ll res=0;
while(num!=0)
{
res+=num%10,num/=10;
}
return res;
}
void solve()
{
ll n,m,ans=0;
cin>>n>>m;
for(int i=n;i<=m;i++)
{
ans+=f(i);
}
cout<<ans;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr),cout.tie(nullptr);
ll t=1;
cin>>t;
while(t--)
{
solve();
}
}
