/in/foo.cc:6:25: warning: multi-character character constant [-Wmultichar]
    6 | static const int MOD = 1'000'000'007;
      |                         ^~~~~
/in/foo.cc:6:33: warning: missing terminating ' character
    6 | static const int MOD = 1'000'000'007;
      |                                 ^
/in/foo.cc:6:33: error: missing terminating ' character
    6 | static const int MOD = 1'000'000'007;
      |                                 ^~~~~
/in/foo.cc:6:25: error: expected ',' or ';' before '\x303030'
    6 | static const int MOD = 1'000'000'007;
      |                         ^~~~~