"""
make a bunch tuples of range() objects for each decoration and then if in the object add n
"""

n, l, max_spook = tuple(map(int, input().split(" ")))

candy = 0

decorations = []

for _ in range(n):
    a, b, s = tuple(map(int, input().split(" ")))
    decorations.append((range(a, b+1), s))

for i in range(l):
    spook_factor = 0

    for deco, spookiness in decorations:
        if i in deco:
            spook_factor += abs(spookiness)
    
    if spook_factor < max_spook:
        candy += 1


if candy == 1:
    print(0) #off by one error lol
else:
    print(candy)