Gym - 102569K Table

There are 4 bars, possibly, having different lengths. Can they be used as the legs of the table, such that:

• The legs stay vertically in the vertices of some rectangle;
• The surface of the table, possibly, sloping, touches all four legs?

Input

The input contains 4 integers a1a1, a2a2, a3a3, a4a4 (1≤ai≤1091≤ai≤109) — the lengths of the bars.

Output

Output "YES" or "NO", depending on it is possible to make a table with the given design or not.

Examples

Input

1 1 1 1

Output

YES

Input

1 5 1 5

Output

YES

Input

1 3 2 2

Output

YES

Input

9 5 11 8

Output

NO
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可以斜着碰，从侧面看就是一个梯形，但是另外一边侧面也可以，就是只要中心点重合就不会折。
要么两两相等，要么求对角线相等，就结束了。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <stack>
#include <queue>
#include <map>
#include <vector>
#include <set>
#include <deque>
#include <cfloat>
#include <algorithm>
typedef long long ll;
using namespace std;

int gcd(int x,int y)
{
    return y?gcd(y,x%y):x;
}

int lcm(int x,int y)
{
    return x/gcd(x,y)*y;
}

int a[5];


int main()
{
    for(int i=0;i<4;i++)
    {
        scanf("%d",&a[i]);
    }
    sort(a,a+4);
    if(a[0]==a[1]&&a[2]==a[3])
    {
        printf("YES");
    }
    else if(a[0]+a[3]==a[1]+a[2])
    {
        printf("YES");
    }
    else printf("NO");

}