Problem	missingnumber
User	Cat
Submission Time	2025-08-27 16:33:27
Score	0
Max Time	N/A
Max Memory	N/A

Compile Error

missingnumber.cpp: In function ‘int main()’:
missingnumber.cpp:13:34: error: expected ‘,’ or ‘;’ before ‘n’
13 | long long expected_sum = 1LL n * (n + 1) / 2;
| ^