head

#include <set>
#include <map>
#include <queue>
#include <stack>
#include <math.h>
#include <vector>
#include <string>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream>
#include <algorithm>
#define zero(a) fabs(a)<eps
#define lowbit(x) (x&(-x))
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define MOD 1000000007
int max(int x,int y){return x>y?x:y;};
int min(int x,int y){return x<y?x:y;};
int max(int x,int y,int z){return max(x,max(y,z));};
int min(int x,int y,int z){return min(x,min(y,z));};
typedef long long LL;
const double PI=acos(-1.0);
const double eps=1e-8;
const int inf=0x3f3f3f3f;
const LL linf=0x3f3f3f3f3f3f3f3fLL;
using namespace std;
int read()
{
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}