提示有未经处理的异常是怎么回事

Question

#include<iostream>
using namespace std;
int main()
{
    int gotbaha(int n);
    int n;
    cout << "请输入一个不小于6的偶数" << endl;
    cin >> n;
    if (n % 2 != 0)cout << "输入有误";
    else
    {
        if (gotbaha(n) >= 1)cout << "得证";
        else cout << "证伪";
    }
    return 0;

}

int gotbaha(int n)
{
    int prime(int x);
    int x = 1;
    int y;
    int m = 0;
    for (; x <= n; x++)
    {
        y = n - x;
        if (prime(x) + prime(y) == 2)
        {
            cout << x << ' ' << y << endl;
            m += 1;
        }

    }
    return m;
}

/*int prime(int x)
{
    int judge;
    if (x == 2)
        return 1;
    else {
        int i;
        for (i = x; (x % i != 0) && i >= 1; i--);
        if (i > 1) judge = 0;
        else judge = 1;

    }
    return judge;
}*/
int prime(int a)
{
    bool n;
    int i;
    if (a == 2) n = 0;
    else {
        for (i = a / 2; a % i != 0 && i >= 1; i--);
        if (i > 1) n = 1;
        else n = 0;

    }
    return n;
}

![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/53148978163614.png "=600 #left")