H,A,D = map(int,input().split())
#何回通常攻撃をするのが最適か
ans = 100001
for i in range(H//A+2):
    HP = H-i*A
    if HP > 0:
        n = i + (-(-HP//D))*3/2
    else:
        n = i
    ans = min(ans,n)
print(ans)