#include <iostream> using namespace std; int countOnes(int n) { int count = 0; for (long long i = 1; i <= n; i *= 10) { int high = n / (i * 10); int low = n % i; int cur = (n / i) % 10; if (cur == 0) { count += high * i; } else if (cur == 1) { count += high * i + low + 1; } else { count += (high + 1) * i; } } return count; } int main() { int n; cin >> n; cout << countOnes(n) << endl; return 0; }