class Solution:
def reverseStr(self, s: str, k: int) -> str:
lo = 0
ans = []
while lo < len(s):
for i in range(min(lo + k, len(s)) - 1, lo - 1, -1):
ans.append(s[i])
for i in range(lo + k, min(lo + 2 * k, len(s))):
ans.append(s[i])
lo += 2 * k
return ''.join(ans)