/in/foo.cc: In function 'int main()':
/in/foo.cc:60:10: error: 'io' was not declared in this scope
   a[i] = io.read();
          ^~
/in/foo.cc:60:10: note: suggested alternative: 'i'
   a[i] = io.read();
          ^~
          i
/in/foo.cc:69:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (ri i = 0; i < n; i++)
                 ~~^~~
/in/foo.cc:80:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (ri i = 0; i < n; i++)
                  ~~^~~
/in/foo.cc:88:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (ri i = 0; i < n; i++)
                 ~~^~~
/in/foo.cc:105:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (ri i = 0; i < n; i++)
                 ~~^~~
/in/foo.cc:116:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (ri i = 0; i < n; i++)
                  ~~^~~
/in/foo.cc:124:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (ri i = 0; i < n; i++)
                 ~~^~~