View Compilation Error

0_0_30454027_23961.cpp: In function 'int main()':
0_0_30454027_23961.cpp:11:2: error: 'set' was not declared in this scope
  set<int> a;
  ^
0_0_30454027_23961.cpp:11:2: note: suggested alternative:
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/set:61:0,
                 from 0_0_30454027_23961.cpp:3:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_set.h:90:11: note:   'std::set'
     class set
           ^
0_0_30454027_23961.cpp:11:6: error: expected primary-expression before 'int'
  set<int> a;
      ^
0_0_30454027_23961.cpp:16:3: error: 'a' was not declared in this scope
   a.clear();
   ^