p02024 City_28808
J: City

Santa decides to deliver a present to a city.

The city has a rectangular shape divided into north-south $ H $ parcels x east-west $ W $ parcels, with one house delivering gifts to each parcel.

The $ X $ th section from the north and the $ Y $ th section from the west are represented by $ (X, Y) $.

Santa moves under the following conditions.

* First, get off at block $ (S, T) $ and start from this place.
* You can move to the adjacent sections in the north, south, east, and west with one move, and you cannot move outside the city.
* You will never enter the area you visited once.



Determine if Santa can visit all the houses in the city.

input

$ H, W, S, T $ are given separated by blanks.

output

Output "Yes" if Santa can visit all the homes in the city, otherwise output "No".

Constraint

* $ H, W $ are integers greater than or equal to $ 2 $ and less than or equal to $ 1 \ 000 \ 000 \ 000 $
* $ S $ is an integer greater than or equal to $ 1 $ and less than or equal to $ H $
* $ T $ is an integer greater than or equal to $ 1 $ and less than or equal to $ W $



Input example 1


4 5 2 3


Output example 1


Yes


For example, you can go to the figure.

<image>

Input example 2


3 3 1 2


Output example 2


No






Example

Input

4 5 2 3


Output

Yes
#include<iostream>
using namespace std;

int main(){
    int h, w, s, t;
    cin >> h >> w >> s >> t;
    if(h > w)   swap(h,w), swap(s,t);
    if(h == 1){
        cout << (t==0||t==w-1 ? "Yes" : "No") << endl;
    }else{
        bool ok = w%2 == 0 || h%2 == 0;
        // wもhも奇数のとき、縦s、横tの線で長方形の区画を4等分したときに
        // 4区画すべての縦横の偶奇がそれぞれ等しければ達成できる
  
        // sやtが端っこの場合は4区画にはならないが、端っこならそもそも
        // 確実に達成できるので、ここでは考える必要は無い
  
        // 4区画の縦横の偶奇が一致している&大元の縦横は奇数->隣り合う区画
        // は縦横 偶偶と奇奇 奇奇なら始点と終点は区画の辺を共有する角、
        // 偶偶なら始点と終点は対角

        // 4区画を一筆書きでうまく埋めることができる

        ok |= (s%2 == t%2);

        cout << (ok ? "Yes" : "No") << endl;
    }
    return 0;
}

4 5 2 3 4 9 2 3 3 1 3 12 4 1 2 3 2 1 2 3 2 1 2 4 3 1 2 4 3 2 2 4 3 4 2 4 4 4 2 4 4 3 2 4 4 3 2 6 3 3 2 6 3 1 2 6 3 1 2 12 1 1 3 12 1 1 3 7 1 2 3 7 1 2 5 7 2 2 5 7 2 2 0 7 2 2 0 14 0 2 0 14 0 0 0 14 0 0 1 14 0 0 1 8 -1 0 1 8 0 -1 1 8 0 -1 2 8 0 -1 0 8 0 -2 0 8 1 -2 0 8 2 -2 0 8 3 -2 0 8 3 -2 0 6 3 -2 1 6 3 -2 1 3 1 -2 1 3 1 -4 1 3 2 -4 1 3 2 -4 2 3 2 -4 2 0 2 -4 3 0 2 -4 6 0 2 -2 6 0 2 -2 5 0 2 -2 8 0 2 -2 11 0 2 -2 9 0 2 -1 9 0 2 -1 9 1 2 -1 7 1 0 -1 7 1 0 -1 12 1 0 -1 2 1 8 5 2 3 4 6 2 3 4 1 2 1 2 1 2 2 2 1 3 4 3 0 2 4 3 3 2 4 3 7 2 4 1 3 2 4 4 3 2 5 8 3 2 6 6 3 2 6 3 1 3 6 3 1 4 12 3 1 0 12 1 2 3 12 1 1 0 7 1 2 4 7 1 2 5 12 3 2 5 7 2 2 1 7 2 2 0 5 -1 2 0 14 1 0 0 14 0 0 1 27 0 1 1 8 -1 0 1 1 0 -1 1 11 0 -1 4 8 0 -2 0 1 1 -2 1 8 1 -4 0 8 3 -2 1 8 0 -2 0 6 5 -2 1 6 3 -2 0 3 0 -1 1 3 0 -4 1 3 2 -4 2 1 2 -4 1 0 3 -4 3 0 0 -4 6 0 2 -2 6 1 3 -2 5 0 0 -2 8 0 1 -2 11 0
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