import random
a,b,c,d = map(int,input().split(' '))
x = 0;y = 0
cs = 0
qz = []
qzs = []
css = 0
kzd = [[c+1,d-2],[c+2,d-1],[c+1,d+2],[c+2,d+1] , [c-1,d+2],[c-2,d+1],[c-1,d-2],[c-2,d-1]]
while True:
    xy = [x, y]
    cpdd = random.randint(0,1)
    if cpdd == 0:
        x+=1
    else:
        y+=1
    if x>a:
        x-=1
    elif x>y:
        y-=1
    for i in range(len(kzd)):
        if kzd[i][0] == x and kzd[i][1] == y:
            x = 0;y = 0
        elif xy in qzs:
            x = 0;y = 0
            css += 1
        elif a == x and b == y:
            qzs.append(x);qzs.append(y)
            qz.append(qzs)
            cs += 1;x = 0;y = 0;qzs = []
    if css == 10:
        break
print(cs)

求大佬给思路