# 卒只能向下和向右走，不能走马的控制点
# 输入处理
x1, y1, x2, y2 = map(int, input().split())  # b点坐标和马的坐标
# 棋盘(0,0)位置为1
l = [[1 for _ in range(25)] for _ in range(25)]
l[x2][y2] = 0
if x2>1 and y2!=0:
    l[x2-2][y2-1]=0
if x2>1 and y2!=20:
    l[x2-2][y2+1]=0
if x2<19 and y2!=0:
    l[x2+2][y2-1]=0
if x2<19 and y2!=20:
    l[x2+2][y2+1]=0
if x2!=0 and y2>1:
    l[x2-1][y2-2]=0
if x2!=0 and y2<19:
    l[x2-1][y2+2]=0
if x2!=20 and y2>1:
    l[x2+1][y2-2]=0
if x2!=20 and y2<19:
    l[x2+1][y2+2]=0
l[0][0]=0
for i in range(x1+1):  # 列
    for j in range(y1+1):  # 行
        if l[i][j] != 0:
            if i == 0 and j > 0:
                l[i][j] = 1
            if i > 0 and j == 0:
                l[i][j] = 1
            else:
                l[i][j] = l[i - 1][j] + l[i][j - 1]
print(l[x1][y1])

感觉没有问题，和标准答案思路也一样，为啥只有60呢