if语句使用--领奖

#include <iostream>
using namespace std;

int main( )
{
    char letter;
    cout <<"请输入你想获奖的字母：" << endl;
    cin >> letter;
    if(letter >= 'a')

    { if( letter <= 'd')
      
        {   cout << "恭喜你获得大奖" << endl;
            if(letter == 'c')
                cout << "你获得了最高奖5000元" << endl;
                else cout << "你获得了3000元奖金" << endl;
        }
    }
   
    else cout << "遗憾！" << endl;
   
    system("pause");
    return 0;
}