answer.code:5:7: error: expected nested-name-specifier before ‘ll’
    5 | using ll=long long;
      |       ^~
answer.code: In function ‘void solve()’:
answer.code:43:30: error: ‘a’ does not name a type
   43 |                         auto a=upper_bound(st.begin(),st.end(),to);
      |                              ^
answer.code:44:30: error: ‘b’ does not name a type
   44 |                         auto b=lower_bound(st.begin(),st.end(),to);
      |                              ^
answer.code:45:30: error: ‘c’ does not name a type
   45 |                         auto c=upper_bound(st.begin(),st.end(),d);
      |                              ^
answer.code:46:30: error: ‘dd’ does not name a type
   46 |                         auto dd=lower_bound(st.begin(),st.end(),d);
      |                              ^~
answer.code:49:36: error: ‘c’ was not declared in this scope
   49 |                                 if(c==st.end()||(*c)>to||(dd==st.begin()&&a==st.end()))
      |                                    ^
answer.code:49:59: error: ‘dd’ was not declared in this scope; did you mean ‘d’?
   49 |                                 if(c==st.end()||(*c)>to||(dd==st.begin()&&a==st.end()))
      |                                                           ^~
      |                                                           d
answer.code:49:75: error: ‘a’ was not declared in this scope
   49 |                                 if(c==st.end()||(*c)>to||(dd==st.begin()&&a==st.end()))
      |                                                                           ^
answer.code:56:36: error: ‘a’ was not declared in this scope
   56 |                                 if(a==st.end()||(*a)>d||(c==st.end()&&b==st.begin()))
      |                                    ^
answer.code:56:58: error: ‘c’ was not declared in this scope
   56 |                                 if(a==st.end()||(*a)>d||(c==st.end()&&b==st.begin()))
      |                                                          ^
answer.code:56:71: error: ‘b’ was not declared in this scope
   56 |                                 if(a==st.end()||(*a)>d||(c==st.end()&&b==st.begin()))
      |                                                                       ^