View Compilation Error

0_0_33251443_27454.cpp: In function 'int main()':
0_0_33251443_27454.cpp:46:25: error: 'struct std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' has no member named 'second'
     ll x=it->first,y=it.second;
                         ^
0_0_33251443_27454.cpp:53:22: error: 'struct std::_Rb_tree_iterator<std::pair<const long long int, long long int> >' has no member named 'second'
       ans=max(ans,it.second); 
                      ^