foo.cc: In function ‘int main()’:
foo.cc:10:17: error: ‘else’ without a previous ‘if’
   10 |                 else
      |                 ^~~~
foo.cc:13:21: error: ‘else’ without a previous ‘if’
   13 |                     else
      |                     ^~~~
foo.cc:16:9: error: ‘else’ without a previous ‘if’
   16 |         else
      |         ^~~~
foo.cc:19:17: error: ‘else’ without a previous ‘if’
   19 |                 else
      |                 ^~~~
foo.cc:22:20: error: ‘else’ without a previous ‘if’
   22 |                    else
      |                    ^~~~