/in/foo.cc: In function 'int main()':
/in/foo.cc:4:14: warning: variable 'n11' set but not used [-Wunused-but-set-variable]
  int n1,n2,m,n11,n22;
              ^
/in/foo.cc:4:18: warning: variable 'n22' set but not used [-Wunused-but-set-variable]
  int n1,n2,m,n11,n22;
                  ^