from math import sqrt
n,k,m = map(int,input().split())

from collections import Counter
d = Counter()
for b in range(3,50):
    for a in range(1,10**6+1):
        x = a
        for i in range(1,b):
            x *= a + i*k
            if x > n: break
        if x <= n:
            d[x] += 1
        else:
            break
    if a==1: break

def check(x): # a(a+k) = x なる a ある？
    v = int((sqrt(float(k)**2 + 4.0*x) - k)/2)
    for a in range(max(1,v-2),v+10):
        if a >= 1 and a*(a+k)==x: return True
        if a*(a+k) > x: return False
    return False

ans = 0
for x,v in d.items():
    if v == m and not check(x):
        ans += 1
    elif v == m-1 and check(x):
        ans += 1

if m == 1:
    v = int((sqrt(float(k)**2 + 4.0*n) - k)/2)
    for a in range(max(1,v-2),v+10):
        if a*(a+k) > n: break
    ans += a-1
    for x in d:
        if check(x): ans -= 1

print(ans)