import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)

n = int(readline())
h = int(readline())
w = int(readline())
print((n - h + 1) * (n - w + 1))

[((5, 0, 5, 30), 'sys.setrecursionlimit', 'sys.setrecursionlimit', ({(5, 22, 5, 29): '(10 ** 7)'}, {}), '(10 ** 7)', False, 'import sys\n')]