import sys
from fractions import Fraction
from functools import cmp_to_key

from typing import List, Tuple

int1 = lambda x: int(x) - 1
input = lambda: sys.stdin.readline().rstrip('\n')
ii = lambda: int(input())
vi = lambda: list(map(int, input().split()))
vi1 = lambda: list(map(int1, input().split()))


def dbg(*args, **kwargs):
    print(*(repr(arg) for arg in args), *(f'{k}: {repr(v)}' for k, v in kwargs.items()),
          sep='; ', file=sys.stderr, flush=True)


def main():
    n, m, k = vi()
    ideg = [0] * n
    odeg = [0] * n
    for i in range(m):
        a, b = vi1()
        odeg[a] += 1
        ideg[b] += 1

    arr = sorted(range(n), key=lambda x: (odeg[x], ideg[x]), reverse=True)
    ans = 0
    for i in range(n):
        if i <= k or odeg[arr[i]] > 0:
            ans += max(0, k - ideg[arr[i]])

    return ans


def _start():
    if (ret := main()) is not None:
        print(*ret) if isinstance(ret, List) or isinstance(ret, Tuple) else print(ret)


if __name__ == '__main__':
    _start()