foo.cc: In function 'int main()':
foo.cc:21:5: error: expected '}' before 'else'
   21 |     else
      |     ^~~~
foo.cc:19:4: note: to match this '{'
   19 |    {
      |    ^
foo.cc:26:13: error: expected '}' at end of input
   26 |     return 0;
      |             ^
foo.cc:4:1: note: to match this '{'
    4 | {
      | ^

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