#include using namespace std; #define rep(i,n) for(int i = 0; i < n; i++) using ll = long long; using graph = vector>; const ll mod = 998244353; const int INF = 1001001001; int digit(int n){ int ret = 0; while(n){ n /= 10; ret++; } return ret; } int main(){ int n; cin >> n; int dgt = digit(n); int ans = 0; for(int i = 2; i <= dgt; i++){ if(i == 2){ int tmp = min(n, 99); ans += tmp / 3 - 3; } else{ if(i == dgt){ int tmp = n, res = 1, cnt; int div = 10; while(tmp){ cnt = (tmp % div) / 3 + 1; if(tmp < 10) cnt -= 1; res *= cnt; tmp /= 10; } ans += res; } else{ ans += pow(4, i - 1) * 3; } } } cout << ans << endl; }