#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

//#define Exchange(num) num = ((num&0X55555555)<<1) + ((num&0Xaaaaaaaa)>>1)
//int main()
//{
//	int num = 10;
//	Exchange(num);
//	printf("%d", num);
//	return 0;
//}





#define OFFESTOF(StructName, NumberName) (size_t)&(((struct stu*)0)->NumberName)

struct stu {
	char name[20];
	int age;
	double achievement;
};


int main()
{
	printf("%d", OFFESTOF(struct stu, achievement));
}