/in/foo.cc: In function 'int main()':
/in/foo.cc:10:11: error: 'maxn' was not declared in this scope
   if(a[i]>maxn)
           ^~~~
/in/foo.cc:13:8: error: 'maxn' was not declared in this scope
  cout<<maxn;
        ^~~~
/in/foo.cc:5:17: warning: unused variable 'minn' [-Wunused-variable]
  int n,a[10005],minn=-1000;
                 ^~~~