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, 'sys.setrecursionlimit', 'sys.setrecursionlimit', False, 'import sys\n')]