#pragma GCC optimize("-O3")
#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define vl vector<ll>
#define vi vector<int>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pb push_back
#define sz(v) (ll)(v.size())
#define f first
#define s second
#define pii pair<int, int>
#define pll pair<ll, ll>
using namespace std;
void solve()
{
ll a, b, i, j;
cin >> a >> b;
ll cnt = 0;
for(i = a; i <= b; i++)
{
bool ok = false;
string s = to_string(i);
for(j = 0; j < sz(s); j++)
{
if(j + 1 < sz(s) && s[j] == s[j+1])
{
ok = true;
break;
}
if(j + 2 < sz(s) && s[j] == s[j+2])
{
ok = true;
break;
}
}
cnt += ok;
}
cout << (b-a+1)-cnt << "\n";
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
ll tests = 1;
//cin >> tests;
while(tests--)
{
solve();
}
}
/*
5 5
1 2 3 4 5
2 3 5 4
3 3 5
1 2 5
2 1 3 3
1 1 3
*/
