no operator ">>" matches these operands

Student * Amark = new Student [iSize];
    for (int i = 0; i < a; i++) 
    {   
        for ( int j = 0; j < iSize; j++)
            cin>>Amark[j].iMark;
            
    
    }

struct Student
{
    char Name [20];
    char Tname [20];
    int Age;
    int iMark [iSize];
    double Average;
};
 
int  _tmain(int argc, _TCHAR* argv[])
{
    srand ((unsigned int)time(0));
    cout<<"How many students ? "<<endl;
    int a;
    cin>>a;
    
    Student * Aname = new Student [20];
    for ( int i = 0; i < a; i++)
        cin>>Aname[i].Name;
    Student * Tname = new Student [20];
    for ( int i = 0; i < a; i++)
        cin>>Tname[i].Tname;
    Student * Aage = new Student [20];
    for ( int i = 0; i < a; i++)
        cin>>Aage[i].Age;
    Student * Amark = new Student [iSize];
    for (int i = 0; i < a; i++) 
    {   
        for ( int j = 0; j < iSize; j++)
            cin>>Amark[j].iMark;
            
    
    }
 
    return 0;
}