#include <bits/stdc++.h> using namespace std; int main() { int n,temp = 0; cin>>n; for(int i = 1;i <= n;i++) { int qian,bai,shi,ge; qian = i / 1000; bai = i / 100 % 10; shi = i / 10 % 10; ge = i % 10; if(qian == 1 || bai == 1 || shi == 1 || ge == 1) { temp += 1; } } cout<<temp<<endl; return 0; }