程序如下，但是无法运行，错误在哪呢，求指教
#include <iostream.h>
int main ()
{
    int score;
    int a;
    cout << "Input score(0~100):;"
    cin >> score;
    a = score / 10;
    switch(a)
    {
        case 10:
        case 9: cout << "优" << endl; break;
        case 8: cout << "良" << endl; break;
        case 7: cout << "中" << endl; break;
        case 6: cout << "及格" << endl; break;
        case 6: cout << "不及格" << endl; break;
    }
    return 0;
}