/in/foo.cc: In function 'int main()':
/in/foo.cc:23:2: error: 'memset' was not declared in this scope
  memset(a,0,sizeof(a)),ans=MAXN;
  ^~~~~~
/in/foo.cc:23:2: note: suggested alternative: 'wmemset'
  memset(a,0,sizeof(a)),ans=MAXN;
  ^~~~~~
  wmemset