from typing import List


def is_valid_walk(walk):
    if len(walk) != 10:
        return False
    
    hasWalk = list()
    
    for m in walk:
        if (m == 'n' and hasWalk.index('s')>=0):
            hasWalk.remove(hasWalk.index('s'))
        elif (m == 's' and hasWalk.index('n')>=0):
            hasWalk.remove(hasWalk.index('n'))
        elif (m == 'e' and hasWalk.index('w')>=0):
            hasWalk.remove(hasWalk.index('w'))
        elif (m == 'w' and hasWalk.index('e')>=0):
            hasWalk.remove(hasWalk.index('e'))
        else:
            hasWalk.append(m)
    
    return len(hasWalk) == 0

print(is_valid_walk(['n','s','n','s','n','s','n','s','n','s']))