import sys
from collections import defaultdict

def solve():
    N, K, M = map(int, sys.stdin.readline().split())
    count = defaultdict(int)
    L = 2

    while True:
        # Check if the minimal product (A=1) is possible
        product = 1
        overflow = False
        for i in range(L):
            term = 1 + i * K
            if product > N // term:
                overflow = True
                break
            product *= term
            if product > N:
                overflow = True
                break
        if overflow:
            break  # No more L to consider

        # Binary search to find the maximum A for current L
        low = 1
        high = N  # Upper bound for A
        best_A = 0
        while low <= high:
            mid = (low + high) // 2
            current_product = 1
            valid = True
            for i in range(L):
                term = mid + i * K
                if term < 1:  # A must be >=1, so terms cannot be <=0
                    valid = False
                    break
                if current_product > N // term:
                    valid = False
                    break
                current_product *= term
                if current_product > N:
                    valid = False
                    break
            if valid:
                best_A = mid
                low = mid + 1
            else:
                high = mid - 1

        if best_A == 0:
            L += 1
            continue

        # Now compute the product for each A from 1 to best_A
        for A in range(1, best_A + 1):
            current_product = 1
            for i in range(L):
                term = A + i * K
                if term < 1:
                    current_product = N + 1
                    break
                if current_product > N // term:
                    current_product = N + 1
                    break
                current_product *= term
                if current_product > N:
                    break
            if current_product <= N:
                count[current_product] += 1

        L += 1

    # Calculate the answer
    ans = 0
    for x in count:
        if 1 <= x <= N and count[x] == M:
            ans += 1
    print(ans)

solve()