1 #include <map>
2 #include <set>
3 #include <cmath>
4 #include <queue>
5 #include <stack>
6 #include <cstdio>
7 #include <string>
8 #include <vector>
9 #include <cstring>
10 #include <iostream>
11 #include <algorithm>
12 #include <functional>
13 using namespace std;
14 #define rep(i,a,n) for (int i=a;i<=n;i++)
15 #define per(i,a,n) for (int i=n;i>=a;i--)
16 #define pb push_back
17 #define mp make_pair
18 #define all(x) (x).begin(),(x).end()
19 #define fi first
20 #define se second
21 #define SZ(x) ((int)(x).size())
22 typedef vector<int> VI;
23 typedef long long ll;
24 typedef pair<int, int> PII;
25 const ll mod = 1000000007;
26 const double eps = 1e-7;
27 // head
