A = []
for i in range(1000) :
    N,K = map(int,input().split())
    s = "Lose" if (N-1)%(K+1) == 0 else "Win"
    A.append(s)

ans = 0
state = 0
for i in range(1000) :
    if state == 0 :
        if A[i] == "Win" :
            ans += 1
            state = 1
    else :
        if A[i] == "Win" :
            state = 0
        else :
            ans += 1
print(ans)