foo.cc:6:1: error: 'package' does not name a type
    6 | package main
      | ^~~~~~~
foo.cc:19:1: error: 'func' does not name a type
   19 | func longestSubstring1(s string, k int) int {
      | ^~~~
foo.cc:43:1: error: 'func' does not name a type
   43 | func getMax(a, b int) int {
      | ^~~~
foo.cc:51:1: error: 'func' does not name a type
   51 | func longestSubstring2(s string, k int) int {
      | ^~~~

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