#include <iostream.h>
//聲明函數(shù)
int add ( int , int);
void main()
{
	//調(diào)用函數(shù)
	cout << add(10 , 20) << endl;
}
//定義函數(shù)
int add(int a, int b)
{
	int iRet = 0;
	iRet = a + b;
	return iRet;
}