class Solution:
    def reverse(self, x: int) -> int:
        sign = 1 if x>0 else -1
        stringre = str(abs(x))
        sumre = 0
        for num, value in enumerate(stringre):
            sumre += int(value)*(10**int(num))
        return sign*sumre*(sumre<2**31)

class Solution(object):
    def reverse(self, x):
        """
        :type x: int
        :rtype: int
        """
        sign = 1 if x>0 else -1
        x = abs(x)
        
        stack = []
        while x>=1:
            stack.append(x%10)
            x = x / 10
        res = 0
        i = 0
        
        while stack:
       
            res += stack.pop() * 10**i
            i += 1
        return res*sign*(res<2**31)

class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:     
        s = ""
        for i in zip(*strs):
            if len(set(i)) == 1:
                s += i[0]
            else:
                break           
        return s