#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<<"\n"; } int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr),cout.tie(nullptr); ll t=1; cin>>t; while(t--) { solve(); } }