#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll ans(ll x){
if(x <= 0) return x;
vector <int> num;
ll dp[20][11][11][2] = {0}; // pref, last1, last2, tight; 10 <=> digit doesnt exist
while(x){
num.push_back(x % 10);
x /= 10;
}
reverse(num.begin(), num.end());
int n = num.size();
for(int i = 0; i < n; i++){
for(int j = 1; j < 10; j++){
if(i == 0 && j == num[i]){
dp[i][10][j][1] = 1;
break;
}
dp[i][10][j][0] = 1;
}
if(i == 0) continue;
for(int j = 0; j < 10; j++)
for(int k = 0; k < 10; k++)
for(int l = 0; l <= 10; l++)
for(int z = 0; z < 2; z++)
if(j != k && j != l && !(z && j > num[i]))
dp[i][k][j][z & (j == num[i])] += dp[i - 1][l][k][z];
}
ll res = 0;
for(int i = 0; i <= 10; i++)
for(int j = 0; j <= 10; j++)
res += dp[n - 1][i][j][0] + dp[n - 1][i][j][1];
return res;
}
int main(){
cin.tie(0);ios_base::sync_with_stdio(0);
ll a, b; cin >> a >> b;
cout << ans(b) - ans(a - 1);
}
