请大家看看问题在哪儿？

#include <iostream.h>

class Ex1
{
private:
int x;
public:
void setdata(int i)
{
x=i*2;
}
void print();
};

class Ex2
{
private:
int y;
public:
void setdata(int j)
{
y=j*j;
}
void print();
};

void Ex1::print()
{
cout<<"class 1:"<<x<<endl;
}

void Ex2::print()
{
cout<<"class 2:"<<y<<endl;
}

void main()
{
Ex1 s;
Ex2 t;
s.setdata(5);
s.print();
t.setdata(5);
t.print();
}

问题描述：
left of".print" must have class/struct/union type