foo.cc: In function ‘int main()’:
foo.cc:16:7: warning: ‘v’ may be used uninitialized [-Wmaybe-uninitialized]
   16 | cout<<v;
      |       ^
foo.cc:5:27: note: ‘v’ was declared here
    5 | int n,a[10005],maxn=-1000,v;
      |                           ^