#include <bits/stdc++.h> #ifdef ULVI #define db(x) cerr<<"[ "<<#x<<" = "<<(x)<<" ]\n" #define dbv(v) cerr<<#v<<" = [ ";for(auto &__x : v)cerr<<__x<<' ';cerr<<"]\n" #define line() cerr<<string(80, '-')<<'\n' #else #define db(x) #define dbv(v) #define line() #endif #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #define all(x) x.begin(),x.end() #define rall(x) x.rbegin(),x.rend() #define ff first #define ss second #define enld endl using namespace std; using namespace __gnu_pbds; typedef long long ll; typedef pair<ll,ll> pll; const ll sz=2e5+100; const ll mod=1e9+7; const ll inf=1e18; template<class T> using indexed_set=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>; mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()); ll dp[50][12][12][2]; ll f(string &num,ll pos,ll last1,ll last2,ll tight){ ll n=num.size(),res=0; ll &d=dp[pos][last1+1][last2+1][tight]; if(d!=-1) return d; if(pos==n) return d=1; ll r=(tight?num[pos]-'0':9); for(ll i=0;i<=r;i++){ if(i==last1 || i==last2) continue; if(i==0 && last1==-1 && last2==-1){ res+=f(num,pos+1,last1,last2,tight&&(i==r)); continue; } res+=f(num,pos+1,i,last1,tight&&(i==r)); } db(res); line(); return d=res; } void solve(){ string l,r; cin>>l>>r; memset(dp,-1,sizeof(dp)); ll a=(l=="0"?0:f(l,0,-1,-1,1)); memset(dp,-1,sizeof(dp)); ll b=f(r,0,-1,-1,1); cout<<b-a+1<<'\n'; } int main(){ //freopen("input.txt","r",stdin); //freopen("output.txt","w",stdout); ios_base::sync_with_stdio(0); cin.tie(0); ll t=1; //cin>>t; for(ll _=1;_<=t;_++){ //cout<<"Scenario #"<<_<<":\n"; solve(); } }