我已经绑定了Atcoder的帐号了，为什么提交还是 Unknown Error？

代码：

#include<bits/stdc++.h>
using namespace std;
int n;
inline int read()
{
	int x = 0, y = 1;
	char c = getchar();
	while (c < '0' || c > '9')
	{
	  if (c == '-')
	    y = -1;
	  c = getchar();
	}
	while (c >= '0' && c <= '9')
	  x = x * 10 + c - '0', c = getchar();
	return x * y;	
}
int main()
{    
    n = read();
    cout << long long (5000 * n + 5000) << endl;
    return 0;
}

求帮助