import sys
sys.setrecursionlimit(10 ** 6)
INF = float('inf')
MOD = 10**9 + 7
MOD2 = 998244353
from collections import defaultdict
def ceil(A,B):
    return -(-A//B)
Ans = defaultdict(lambda:-1)

def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LC(): return list(sys.stdin.readline().rstrip())
def IC(): return [int(c) for c in sys.stdin.readline().rstrip()]
def MI(): return map(int, sys.stdin.readline().split())
H,A = MI()
Ans[0]=0
def dfs(h):
    if(Ans[h]==-1):
        ac = dfs(h//A)
        Ans[h] = 1+2*ac
        return Ans[h]
    else:
        return Ans[h]
dfs(H)
print(Ans[H])