库特上的Xcode "expected unqualified-id"

我正在尝试制作一个程序来计算 7 种不同纵横比的用户输入数字的 y 分量。这可能是顶部声明中某个地方的简单问题，但我对 c++ 的经验很少。我正在用xcode编写。谢谢！

我收到以下错误消息：

19：13： 二进制表达式的操作数无效（"std：：__1：：basic_istream"和"）

32：6：预期的非限定 ID

    //
    //  aspect1.cpp
    //  aspectRatioCalculator
    //

    #include <iostream>
    using namespace std;
    int main()
    {
    int a;
    cout << "Enter a number to calculate its complements at multiple aspect ratios." << endl;
    cin>> a >> endl;
    int b = (a*9)/17;
    int c = (a*9)/16;
    int d = (a*5)/8;
    int e = (a*4)/5;
    int f = (a*3)/5;
    int g = (a*3)/4;
    int h = (a*2)/3;
    cout << "17:9 | " << a << ":" << b << endl;
    cout << "16:9 | " << a << ":" << c << endl;
    cout << " 8:5 | " << a << ":" << d << endl;
    cout << " 5:4 | " << a << ":" << e << endl;
    cout << " 5:3 | " << a << ":" << f << endl;
    cout << " 4:3 | " << a << ":" << g << endl;
    cout << " 3:2 | " << a << ":" << h << endl;
    }