#include <bits/stdc++.h>
#define pb push_back
#define s second
#define f first
#define ll long long
#define int ll
using namespace std;
int p[25];
signed main (){
ios_base::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
p[0] = 1;
for (int i = 1; i <= 18; i++)
p[i] = p[i - 1]*10;
int a,b,ans=0;
cin>>a>>b;
for (int i = a; i <= b; ){
int q=1,cnt=0,x=0;
for (int j = 18; j >= 0; j--){
if (i < p[j]) continue;
cnt++;
int y = (i/p[j])%10;
x = x*10 + y;
// if (i== 199)
// cout<<cnt<<" "<<y<<" "<<p[j]<<" "<<p[j + 1]<<" "<<p[j + 2]<<endl;
if ((cnt > 1 && y == (i/p[j + 1])%10) || (cnt > 2 && y == (i/p[j + 2])%10)){
// cout<<"num = "<<i<<" "<<cnt<<" "<<j<<endl;
q=0;
x++;
x *= p[j];
// cout<<"num = "<<i<<" "<<x<<endl;
// exit(0);
break;
}
}
if (q) ans++,i++;
else i = x;
}
cout<<ans;
}
