898A - Rounding - CodeForces Solution

#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
using namespace std;

#define ll long long

ll gcd(ll a, ll b) { return ((b == 0) ? a : gcd(b, a % b)); }
ll lcm(ll a, ll b) { return (b / gcd(a, b)) * a; }

void Candidate_Elde7k() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr), cout.tie(nullptr);
}

int main() {
	Candidate_Elde7k();
	int n; cin >> n;
	if (n % 10 == 0) {
		cout << n << "\n";
	}
	else if (n < 10) {
		if (n >= 5) {
			cout << 10 << "\n";
		}
		else{
			cout << 0 << "\n";
		}
	}
	else {
		if (n % 10 < 5) {
			cout << n / 10 << 0 << "\n";
		}
		else {
			n /= 10;
			n++;
			cout << n << 0 << "\n";	
		}
	}
}