def comp(x):
    if x=="NORTH":
        return "SOUTH"
    if x=="WEST":
        return "EAST"
    if x=="SOUTH":
        return "NORTH"
    if x=="EAST":
        return "WEST"

def directionReductions(arr):
    result=[]
    i=0
    while i< len(arr)-1:
        if arr[i]==comp(arr[i+1]):
            i+=1
        else:
            if len(result)==0:
                result.append(arr[i])
            elif result[-1]==comp[arr[i]]:
                result.pop()
            else:
                result.append(arr[i])
        i+=1
    if len(result)==0:
        result.append(arr[i])
    elif result[-1]==comp[arr[i]]:
        result.pop()
    else:
        result.append(arr[i])

    return result