foo.cc: In function 'int main()':
foo.cc:35:18: warning: 'b' may be used uninitialized [-Wmaybe-uninitialized]
   35 |         cout<<b<<" "<<a<<endl;
      |                  ^~~
foo.cc:23:21: note: 'b' was declared here
   23 |         int n,b1,b2,b,a1,a2,a;
      |                     ^
foo.cc:35:23: warning: 'a' may be used uninitialized [-Wmaybe-uninitialized]
   35 |         cout<<b<<" "<<a<<endl;
      |                       ^
foo.cc:23:29: note: 'a' was declared here
   23 |         int n,b1,b2,b,a1,a2,a;
      |                             ^