/in/foo.cc: In function 'int main()':
/in/foo.cc:8:13: warning: unused variable 'maxa' [-Wunused-variable]
  int n,m,it,maxa=0;
             ^~~~
/in/foo.cc:32:22: warning: 'it' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(b>a[it-1]&&b<a[it+1])cout<<"No";
                    ~~^~