/in/foo.cc: In function 'int main()':
/in/foo.cc:44:6: error: 'i' was not declared in this scope
  for(i=0;i<n2;i++)
      ^
/in/foo.cc:46:6: error: 'i' was not declared in this scope
  for(i=0;i<n3;i++)
      ^