问一个关于cin的问题，好奇怪啊！

#include <iostream>
using namespace std;

struct node
{
int m_value;
node *next;
};

void main()
{
int value,value2;
node *top = 0;
node *top2 = 0;

cout<<"构造链表1:"<<endl;
while (cin>>value)
{
node * p = (node *)malloc(sizeof(node));
p->m_value = value;
p->next = NULL;
if (top == NULL)
{
top = p;
}
else
{
p->next = top;
top = p;
}
}

cout<<"构造链表2:"<<endl;
///////////////////////////////////////////下面的cin不等我输入就直接false
while (cin>>value2)
{
node * p = (node *)malloc(sizeof(node));
p->m_value = value2;
p->next = NULL;
if (top2 == NULL)
{
top2 = p;
}
else
{
p->next = top2;
top2 = p;
}
}
}