# _*_ coding:utf-8 _*_

def trims(s):
    if len(s)==0:
        return s

    result = s
    n=0

    while n<len(result):
        if result[n]==' ':
            result=result[1:]
        else:
            break
        n+=1

    n=len(result)

    while n>0:
        if result[n-1]==' ':
            result=result[-len(result):-1]
        else:
            break
        n-=1
    
    return result