import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = 18446744073709551615
# inf = 4294967295
md = 10**9+7
# md = 998244353

def prime_factorization(a):
    pp, ee = [], []
    if a & 1 == 0:
        pp += [2]
        ee += [0]
        while a & 1 == 0:
            a >>= 1
            ee[-1] += 1
    p = 3
    while p**2 <= a:
        if a%p == 0:
            pp += [p]
            ee += [0]
            while a%p == 0:
                a //= p
                ee[-1] += 1
        p += 2
    if a > 1:
        pp += [a]
        ee += [1]
    return pp, ee

# a!にmが何個入っているか
def cnt(a, p):
    d = p
    res = 0
    while d <= a:
        res += a//d
        d *= p
    return res

n, k, m = LI()
pp, ee = prime_factorization(m)
# pDB(pp,ee)

ans = inf
for p, e in zip(pp, ee):
    cur = cnt(n, p)-cnt(n-k, p)-cnt(k, p)
    ans = min(ans, cur//e)
print(ans)