#include<bits/stdc++.h>
#pragma GCC target ("avx,avx2,fma")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
typedef long long ll;
typedef long double ld;
#define SPEED ios_base::sync_with_stdio(false); cin.tie(0), cout.tie(0)
#define rall(v) (v).rbegin(),(v).rend()
#define all(v) (v).begin(),(v).end()
#define OK cerr<<"OK"<<endl<<flush
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define F first
#define S second
#define y0 jahdakdh
#define y1 jahsadakdakdh
#define endl '\n'
using namespace std;
const ll MOD=1e9+7;
// mt19937 rng(std::chrono::system_clock::now().time_since_epoch().count());
ll a, b, p[20];
ll ans;
ll check(ll x)
{
string s=to_string(x);
int n=s.length();
s+='-';
for(int i=0; i<n-1; i++)
{
if(s[i]==s[i+1]) return n-(i+1)-1;
else if(s[i]==s[i+2]) return n-(i+2)-1;
}
return -1;
}
int main()
{
SPEED;
p[0]=1;
for(int i=1; i<=18; i++)
p[i]=p[i-1]*10;
cin>>a>>b;
for(ll i=a; i<=b;)
{
ll e=check(i);
if(e==-1) ans++, e++;
//cout<<i<<' '<<e<<endl;
i=(i/p[e]*p[e])+p[e];
}
cout<<ans<<endl;
return 0;
}
