#include <array> #include <cassert> #include <cstddef> #include <cstring> #include <functional> #include <iostream> #include <algorithm> #include <chrono> #include <queue> #include <random> #include <set> #include <string> #include <vector> using namespace std; #ifdef LOCAL #include "debug.h" #else #define debug(...) 42 #endif typedef long long ll; typedef long double ld; typedef pair<int,int> pii; typedef vector<int> vi; typedef vector<vi> vvi; #define all(x) (x).begin(), (x).end() #define isz(x) (int)(x.size()) #define int ll mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()); const int sz = 1200, inf = 1000000000; const ll mod = 1000000007, INF = 1000000000000000000; const int D = 11; const int N = 20; int dp[N][D][D][2]; string s; int solve(int pos, int d1, int d2, int block) { if (pos == isz(s)) return 1; if (dp[pos][d1][d2][block] != -1) return dp[pos][d1][d2][block]; int res = 0; if (!d2) res += solve(pos + 1, d1, d2, 0); int st = 1 + (d2 == 0 ? 1 : 0); if (!block) { for (int d3 = st; d3 < D; d3++) { if (d3 != d1 && d3 != d2) { res += solve(pos + 1, d2, d3, 0); } } } else { int e = s[pos] - '0' + 1; for (int d3 = st; d3 <= e; d3++) { if (d3 != d1 && d3 != d2) { if (d3 == e) { res += solve(pos + 1, d2, d3, 1); } else { res += solve(pos + 1, d2, d3, 0); } } } } return dp[pos][d1][d2][block] = res; } int solve(int x) { memset(dp, -1, sizeof(dp)); s = to_string(x); return solve(0, 0, 0, 1); } void precompute() {} signed main() { ios::sync_with_stdio(false); cin.tie(nullptr); #ifdef LOCAL freopen("err.log", "w", stderr); freopen("in.txt", "r", stdin); #endif precompute(); int a, b; cin >> a >> b; cout << solve(b) - solve(a - 1) << '\n'; return 0; }