УПРОСТИТЕ НА PYTHON 3 a = [int(i) for i in input().split()]
su = 0
for i1 in range(a[0], a[1] + 1):
for i2 in range(a[1], a[2] + 1):
for i3 in range(a[2], a[3] + 1):
if i1 + i2 > i3:
su += 1
print(su)

My marvelous journey began when we, all of a sudden, went to the safari in Kenya in the middle of a summer. Having flown across the ocean we found ourselves surrounded by roaring nature. National parks fascinated us with picturesque landscapes; they were vivid and swarming with wildlife. Elephants and giraffes were peacefully eating leaves, lion prides were resting in preparation for the night hunt. An antelope herd ran by, probably spooked by some predators. Graceful zebras were grazing quietly in the plains, and imposing buffaloes were going to a watering place unhurriedly. At nights we heard hyenas’ cries, that disturbed a night hunt for nocturnal predators. Screams of the eagles, soaring high in the sky, woke everybody up at dawns. We’ve spent in Africa only one week, but it was wonderful and unforgettable! Having gone to African safari once you won’t ever be able to resist the urge to come back!

My marvelous journey began when we, all of a sudden, went to the safari in Kenya in the middle of a summer. Having flown across the ocean we found ourselves surrounded by roaring nature. National parks fascinated us with picturesque landscapes; they were vivid and swarming with wildlife. Elephants and giraffes were peacefully eating leaves, lion prides were resting in preparation for the night hunt. An antelope herd ran by, probably spooked by some predators. Graceful zebras were grazing quietly in the plains, and imposing buffaloes were going to a watering place unhurriedly. At nights we heard hyenas’ cries, that disturbed a night hunt for nocturnal predators. Screams of the eagles, soaring high in the sky, woke everybody up at dawns. We’ve spent in Africa only one week, but it was wonderful and unforgettable! Having gone to African safari once you won’t ever be able to resist the urge to come back!