문제
풀이
#include <iostream>
using namespace std;
void solve(void) {
int n; cin >> n;
int ans = 1, cur = 11;
while (n >= cur) {
cur = 10 * cur + 1;
ans++;
}
cout << ans;
}
int main(void) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
solve();
return 0;
}