two or more data types in declaration of `main'

#include <iostream>
#pragma pack(8)
using std::cout;
using std::endl;
struct example1
{
 short a;
 long b;
}

struct example2
{
 char c;
 example1 struct1;
 short e;
}

#pragma pack()
int main()
{
example2 struct2;
 cout<<(unsigned int)(&struct2.struct1)-(unsigned int)(&struct2);
 system("pause");
 return 0;
}

struct结构后面缺少；符号错误