#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int ll // delete if causing problems
#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define mod(a) (a+MOD)%MOD
#define all(a) a.begin(), a.end()
#define sz(a) (int)a.size()
const int maxn = 3e5+10; // change when needed!
const int MOD = 1e9+7; // same!
const int INF = 2e9;
const ll LINF = 4e18;
int n, m, x, y, l, r, k, q, t;
map<int, int> M, N;
string a, b,s;
int dp[20][12][12][2];
bool chk(string a){
int n = (int)a.size();
for(int i = 0; i < n-1; i++){
if(i<n-2 and a[i]==a[i+2]) return false;
if(a[i]==a[i+1]) return false;
}
return true;
}
int recur(int pos=0, int last=10, int last2=10, bool sm=0)
{
int n = (int)s.size();
if(pos==n) return dp[pos][last][last2][sm]=1;
if(dp[pos][last][last2][sm]!=-1) return dp[pos][last][last2][sm];
int limit = 9, ans = 0;
if(!sm) limit = s[pos]-'0';
for(int d = 0; d <= limit; d++)
{
if(d==last or d==last2) continue;
bool SM = sm; if(!SM and d<limit) SM=true;
ans+=recur(pos+1, d, last, SM);
}
return dp[pos][last][last2][sm]=ans;
}
int32_t main()
{
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> a >> b; memset(dp, -1, sizeof(dp)); s = b;
int ans = recur();
memset(dp, -1, sizeof(dp)); s = a;
cout << ans-recur()+chk(a);
}
