memes

# all = [int(a) for a in input().split(" ")]
# good = set([int(a) for a in input().split(" ")])
# bad = set([int(a) for a in input().split(" ")])
#
#
# good &= set(all)
# bad &= set(all)
# index = 0
#
#
# def freq(a, arr):
#     return sum(1 for i in arr if a == i)
#
#
# ht = {}
# for a in all:
#     if a in ht:
#         ht[a] += 1
#     else:
#         ht[a] = 1
#
# for a in good:
#     index += ht[a]
# for a in bad:
#     index -= ht[a]
# print(index)

# nums = [int(a) for a in input().split(" ")]
# print("\n".join(" ".join(str(i*j) for i in range(1, nums[1] + 1)) for j in range(1, nums[0] + 1)))
#
# inpdict = []
#
# for _ in range(int(input())):
#     inpstr = input().split(" - ")
#     translations = inpstr[1].split(", ")
#     for t in translations:
#         inpdict.append((t, inpstr[0]))
#
# table = {}
# for (w, t) in inpdict:
#     if w in table:
#         table[w].append(t)
#     else:
#         table[w] = [t]
#
#
# print(len(table))
# print("\n".join(sorted(a[0] + " - " + ", ".join(sorted(a[1])) for a in table.items())))


# def generate_n_primes(N):
#     primes = [2]
#     chkthis = 3
#     while len(primes) < N:
#         ptest = [chkthis for i in primes if chkthis % i == 0]
#         primes += [] if ptest else [chkthis]
#         chkthis += 2
#     return primes[N - 1]
#
#
# print(generate_n_primes(int(input())))

# test_string = input()
#
# freq_table = {}
# for c in test_string:
#     if c in freq_table and freq_table[c] == 1:
#         freq_table[c] -= 1
#     elif c in freq_table and freq_table[c] == 0:
#         freq_table[c] += 1
#     else:
#         freq_table[c] = 1
#
# if sum(freq_table.values()) > 1:
#     print("NO")
# else:
#     print("YES")