View Compilation Error

0_0_38789663_5365.cpp: In function 'void solve()':
0_0_38789663_5365.cpp:20:37: error: 'sum' was not declared in this scope
   20 |                 if(n%circle<=mid*2) sum=circle*2;//当最后一个周期长度小于等于mid*2时,2的个数即为circle*2
      |                                     ^~~
0_0_38789663_5365.cpp:21:22: error: 'sum' was not declared in this scope
   21 |                 else sum=circle*2+mid*2-n%circle;//当最后一个周期长度大于mid*2时,那么2的个数即为circle*2+mid*2-n%circle
      |                      ^~~
0_0_38789663_5365.cpp:23:20: error: 'sum' was not declared in this scope
   23 |                 if(sum<=mid) r=mid;
      |                    ^~~