[백준 2839] [greedy] 설탕배달

백준 2839번 [설탕배달]

풀이)

n=int(input())
cnt = 0
for x in range(n//5,-1,-1) :
    n_ = n - (5*x)
    if n_%3 == 0 :
        cnt+= (n_//3)
        cnt+= x
        print(cnt)
        break
if cnt == 0 :
    print(-1)