n,k,m=map(int,input().split())

d={}
v=m
i=2
while i*i<=v:
  if v%i==0:
    d[i]=0
    while v%i==0:
      d[i]+=1
      v//=i
  i+=1
if v>1:
  d[v]=1

def solve(a,b):
  c=0
  v=a
  u=b
  while v//u>0:
    c+=v//u
    u*=b
  return c

print(min((solve(n,v)-solve(k,v)-solve(n-k,v))//d[v] for v in d))