foo.cc: In function 'int main()':
foo.cc:16:14: error: 'n' was not declared in this scope
  printf("%d",n);
              ^
foo.cc:16:14: note: suggested alternative: 'na'
  printf("%d",n);
              ^
              na
foo.cc:6:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&k);
  ~~~~~^~~~~~~~~