n = int(input())
s = input()
m = [[0 for j in range(26)] for i in range(26)]
A = ord('A')
for i in range(n - 1):
m[ord(s[i]) - A][ord(s[i + 1]) - A] += 1
x, y = 0, 0
for i in range(26):
for j in range(26):
if m[i][j] > m[x][y]:
x, y = i, j
print(chr(A + x)+ chr(A + y))
MATCHES Playing with Matches | HRDSEQ Hard Sequence |
DRCHEF Doctor Chef | 559. Maximum Depth of N-ary Tree |
821. Shortest Distance to a Character | 1441. Build an Array With Stack Operations |
1356. Sort Integers by The Number of 1 Bits | 922. Sort Array By Parity II |
344. Reverse String | 1047. Remove All Adjacent Duplicates In String |
977. Squares of a Sorted Array | 852. Peak Index in a Mountain Array |
461. Hamming Distance | 1748. Sum of Unique Elements |
897. Increasing Order Search Tree | 905. Sort Array By Parity |
1351. Count Negative Numbers in a Sorted Matrix | 617. Merge Two Binary Trees |
1450. Number of Students Doing Homework at a Given Time | 700. Search in a Binary Search Tree |
590. N-ary Tree Postorder Traversal | 589. N-ary Tree Preorder Traversal |
1299. Replace Elements with Greatest Element on Right Side | 1768. Merge Strings Alternately |
561. Array Partition I | 1374. Generate a String With Characters That Have Odd Counts |
1822. Sign of the Product of an Array | 1464. Maximum Product of Two Elements in an Array |
1323. Maximum 69 Number | 832. Flipping an Image |