#include <bits/stdc++.h>

using namespace std;


int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);

    int h, w, r, c;

    cin >> h >> w >> r >> c;

    int result = 0;
    if(h > 1){
        result++;
    }

    if(w > 1){
        result++;
    }

    if(r != 1 && r != h){
        result++;
    }

    if(c != 1 && c != w){
        result++;
    }

    cout << result;

    cout << flush;

    return 0;
}