我做了一个判断素数的程序

#include<iostream>

using namespace std;

int prime(long long n,bool g);

int main()
{
	long long num;
	int tf;
	cin>>num;
	tf = prime(num,tf);
	if(tf)
	{
		cout<<"yes";
	}
	else
	{
		cout<<"no";
	}
}

int prime(long long n,bool judge);
{
	for(int i = 0 ; i <= n/2 ; i++)
	{
		if(n % i == 0)
		{
			judge = false;
			break;
		}
		else
		{
			judge = true;
			break;
		}
	}
	return;
}

可是为什么会报错error: expected unqualified-id

错误：应为非限定id