Here is the link to the contest.
A. Valid Parentheses
Solution
Code
B. Chef Jamie
To solve this problem we have to use stack
def solve():
C. Experiment
To solve this problem we have to use stack
Code
</spoiler>
[D. Minimum Park Lighting Cost](https://codeforces.net/gym/537575/problem/D)
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To solve this problem we have to use stack
</spoiler>
<spoiler summary="Code">
def solve():
</spoiler>
[E. Secure The Castle](https://codeforces.net/gym/537575/problem/E)
-------------------------------------------------------------------
To solve this problem we have to use stack
</spoiler>
<spoiler summary="Code">
def solve():
```
