stonesForCrown.py

from collections import Counter

def stonesForCrown(stones):
    c = Counter(stones)
    num = 0
    val = 0
    l = sorted(c.items(), key = lambda x:(x[1], x[0]), reverse=True)
    for x in l:
        if num != x[1]:
            num = x[1]
            val = x[0]
        else:
            return val
    else:
        return -1