#include<iostream> #include<vector> #include<algorithm> #include<string> #include<cmath> #include<set> #include<map> #include<queue> #include<stack> #include<unordered_map> #include<unordered_set> using namespace std; using ll = long long; ll mod = 1e9 + 7; ll gcd(ll a, ll b) { if (b == 0)return a; else return gcd(b, a % b); } ll get(ll n) { vector<vector<vector<vector<ll>>>>dp(19, vector<vector<vector<ll>>>(11, vector<vector<ll>>(11, vector<ll>(2)))); dp[0][10][10][1] = 1; string s = to_string(n); for (ll i = 1; i <= s.size(); i++) { for (ll k = 0; k <= 10; k++) { for (ll x = 0; x <= 10; x++) { for (ll j = 0; j <= 10; j++) { if (k == 0 && x == 10)continue; if (k == 10) { dp[i][k][k][0] = 1; } else if (x == 10) { if (i != 1) { dp[i][k][x][0] = 1; } else if (k < (s[i - 1] - '0')) { dp[i][k][x][0] = 1; } else if (k == (s[i - 1] - '0')) { dp[i][k][x][1] = 1; } } else { if (k != x && k != j && j != x) { if (k < (s[i - 1] - '0')) { dp[i][k][x][0] += dp[i - 1][x][j][0]; dp[i][k][x][0] += dp[i - 1][x][j][1]; } else if (k == (s[i - 1] - '0')) { dp[i][k][x][1] += dp[i - 1][x][j][1]; dp[i][k][x][0] += dp[i - 1][x][j][0]; } else { dp[i][k][x][0] += dp[i - 1][x][j][0]; } } } } } } } ll ans = 0; for (ll i = 0; i <= 9; i++) { for (ll j = 0; j <= 10; j++) { ans += dp[s.size()][i][j][0]; ans += dp[s.size()][i][j][1]; } } return ans; } void solve() { ll l, r; cin >> l >> r; if (l == 0) { cout << get(r) + 1 << endl; } else cout << get(r) - get(l - 1) << endl; //cout<<get(r)<<" " << get(l-1) << endl; } signed main() { ios_base::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr); ll t = 1; //cin >> t; while (t--) { solve(); } }