/in/foo.cc: In function 'void dfs(const long long int&, const long long int&, const long long int&, const long long int&)':
/in/foo.cc:53:21: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   dfs(x + 1, r1, l2 + x - l1, r2 - 1);
                  ~~~^~~
/in/foo.cc:53:21: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   dfs(x + 1, r1, l2 + x - l1, r2 - 1);
                  ~~~^~~
/in/foo.cc:53:21: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   dfs(x + 1, r1, l2 + x - l1, r2 - 1);
                  ~~~^~~
/in/foo.cc:53:21: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   dfs(x + 1, r1, l2 + x - l1, r2 - 1);
                  ~~~^~~
/in/foo.cc:53:21: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   dfs(x + 1, r1, l2 + x - l1, r2 - 1);
                  ~~~^~~
/in/foo.cc:53:21: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   dfs(x + 1, r1, l2 + x - l1, r2 - 1);
                  ~~~^~~