from collections import defaultdict
N,K,M = map(int,input().split())
class get_prime():#使うたびにクラスの定義が必要。self.revの使い回しNG
    def __init__(self):
        self.rev = []
    def prime(self,n):
        if n == 1:
            return self.rev
        for i in range(2,int(n**0.5)+1):
            if n % i == 0:
                self.rev.append(i)
                self.prime(int(n/i))
                break
        else:
            self.rev.append(n)
        return self.rev
gp = get_prime()
mp = gp.prime(M)
pdic = defaultdict(int)
for p in mp:
    pdic[p] += 1

def f(l,r,x,p):
    al = (l + pow(p,x) -1) // pow(p,x)
    al = max(al,1)
    ar = r //pow(p,x)
    if ar >= 1 and al <= ar:
        return ar - al + 1
    else:
        return 0
def g(l,r,p):
    x = 1
    res = 0
    while pow(p,x) <= r:
        res += f(l,r,x,p)
        x += 1
    return res
INF = float('inf')
UP = INF
DOWN = INF
for p in pdic.keys():
    up = g(N-K+1,N,p)//pdic[p]
    down = g(1,K,p) //pdic[p]
    UP = min(UP,up)
    DOWN = min(down,down)
print(UP - DOWN)