Submission #6685495

---

Source Code Expand

#include<bits/stdc++.h>
using namespace std;
int a,b,c,d,e;
int main(){
	ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	cin>>a;
	for(b=1; b<=a; b++){
		c=b;d=0;
		while(c>0){
			c/=10;
			d++;
		}
		if(d%2==1) e++;
	}
	cout<<e;
	return 0;
}

Submission Info

Judge Result