n = int(input())
la = -1
cnt = 0
flg = True
lac = -1
s = input().split()
for i in range(n):
x = int(s[i])
if (x == lac):
cnt += 1
else:
if (la != -1 and la != cnt):
flg = False
break
else:
if (cnt != 0):
la = cnt
cnt = 1
lac = x
if (flg == False or (la != -1 and la != cnt)):
print('NO')
else:
print('YES')994. Rotting Oranges | 983. Minimum Cost For Tickets |
973. K Closest Points to Origin | 969. Pancake Sorting |
967. Numbers With Same Consecutive Differences | 957. Prison Cells After N Days |
946. Validate Stack Sequences | 921. Minimum Add to Make Parentheses Valid |
881. Boats to Save People | 497. Random Point in Non-overlapping Rectangles |
528. Random Pick with Weight | 470. Implement Rand10() Using Rand7() |
866. Prime Palindrome | 1516A - Tit for Tat |
622. Design Circular Queue | 814. Binary Tree Pruning |
791. Custom Sort String | 787. Cheapest Flights Within K Stops |
779. K-th Symbol in Grammar | 701. Insert into a Binary Search Tree |
429. N-ary Tree Level Order Traversal | 739. Daily Temperatures |
647. Palindromic Substrings | 583. Delete Operation for Two Strings |
518. Coin Change 2 | 516. Longest Palindromic Subsequence |
468. Validate IP Address | 450. Delete Node in a BST |
445. Add Two Numbers II | 442. Find All Duplicates in an Array |