题目链接
思路:
(a little water…咳咳咳…just a little\手动滑稽)。
代码:
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define IOS ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
const int N=55;
const int M=4e5+8;
const double eps=1e-8;
const int mod=1e9+7;
const int inf=0x7fffffff;
const double pi=3.1415926;
signed main()
{
IOS;
cout<<"0.666667"<<endl;
return 0;
}