Prime number check with function

#include <bits/stdc++.h>

using namespace std;

bool isprime(int n)
{
    if (n == 1)
        return false;

    for (int i = 2; i * i <= n; i++)
        if (n % i == 0)
            return false;

    return true;
}

int main()
{
    int n;

    cin >> n;

    if (isprime(n))
        cout << "prime" << endl;
    else
        cout << "composite" << endl;

    return 0;
}