---

n, k = map(int, input().split())
s = input().strip()

cnt = [0] * 676

for i in range(n - 1):
    a = ord(s[i]) - ord('a')
    b = ord(s[i + 1]) - ord('a')
    cnt[a * 26 + b] += k

if k > 1:
    a = ord(s[-1]) - ord('a')
    b = ord(s[0]) - ord('a')
    cnt[a * 26 + b] += k - 1

best = max(cnt)
idx = cnt.index(best)

print(chr(idx // 26 + ord('a')) +
      chr(idx % 26 + ord('a')))
print(best)