#include <iostream>
using namespace std;

bool isPrime(unsigned int);

int main() {
    unsigned int number;
    cin>>number;
    if(isPrime(number))
        cout<<"Prime"<<endl;
    if(!(isPrime(number)))
        cout<<"Not Prime"<<endl;
    return 0;
}

bool isPrime(unsigned int number){
    if (number < 2)
        return false;
    
    for (int i=2; i<(number/2 + 1); i++){
        if(number%i==0)
            return false;
    }
    return true;
}

cc1plus: warnings being treated as errors
In function 'bool isPrime(unsigned int)':
Line 20: warning: comparison between signed and unsigned integer expressions