answer.code:4:7: error: ‘ldb’ does not name a type
    4 | const ldb pi=acosl(-1);
      |       ^~~
answer.code:5:13: error: ‘ldb’ does not name a type
    5 | int n,id[N];ldb s,ans,val[N];pair<int,int>A[N];
      |             ^~~
answer.code: In function ‘int main()’:
answer.code:11:23: error: ‘ldb’ does not name a type
   11 |                 const ldb x=cosl(pi*k/B),y=-sinl(pi*k/B);
      |                       ^~~
answer.code:12:37: error: ‘val’ was not declared in this scope
   12 |                 for(int i=0;i<n;++i)val[i]=A[i].first*x+A[i].second*y,id[i]=i;
      |                                     ^~~
answer.code:12:55: error: ‘x’ was not declared in this scope
   12 |                 for(int i=0;i<n;++i)val[i]=A[i].first*x+A[i].second*y,id[i]=i;
      |                                                       ^
answer.code:12:69: error: ‘y’ was not declared in this scope
   12 |                 for(int i=0;i<n;++i)val[i]=A[i].first*x+A[i].second*y,id[i]=i;
      |                                                                     ^
answer.code: In lambda function:
answer.code:13:66: error: ‘val’ was not declared in this scope
   13 |                 sort(id,id+n,[&](const int&x,const int&y){return val[x]<val[y];});
      |                                                                  ^~~
answer.code: In function ‘int main()’:
answer.code:14:17: error: ‘s’ was not declared in this scope
   14 |                 s=0;for(int i=0;i<n;++i)ans+=val[id[i]]*i-s,s+=val[id[i]];
      |                 ^
answer.code:14:41: error: ‘ans’ was not declared in this scope; did you mean ‘abs’?
   14 |                 s=0;for(int i=0;i<n;++i)ans+=val[id[i]]*i-s,s+=val[id[i]];
      |                                         ^~~
      |                                         abs
answer.code:14:46: error: ‘val’ was not declared in this scope
   14 |                 s=0;for(int i=0;i<n;++i)ans+=val[id[i]]*i-s,s+=val[id[i]];
      |                                              ^~~
answer.code:15:38: error: ‘ans’ was not declared in this scope; did you mean ‘abs’?
   15 |                 s=0;for(int i=n;i--;)ans+=s-val[id[i]]*(n-i-1),s+=val[id[i]];
      |                                      ^~~
      |                                      abs
answer.code:15:45: error: ‘val’ was not declared in this scope
   15 |                 s=0;for(int i=n;i--;)ans+=s-val[id[i]]*(n-i-1),s+=val[id[i]];
      |                                             ^~~
answer.code:17:40: error: ‘ans’ was not declared in this scope; did you mean ‘abs’?
   17 |         cout<<fixed<<setprecision(10)<<ans*pi/B/4<<'\n';
      |                                        ^~~
      |                                        abs
answer.code:17:44: error: ‘pi’ was not declared in this scope
   17 |         cout<<fixed<<setprecision(10)<<ans*pi/B/4<<'\n';
      |                                            ^~