foo.cc: In function 'int WeekdayOfTheFirstDay(int, int)':
foo.cc:32:25: error: a function-definition is not allowed here before '{' token
   32 | int IsLeapYear(int year){
      |                         ^
foo.cc:36:25: error: a function-definition is not allowed here before '{' token
   36 | int DaysOfYear(int year){
      |                         ^
foo.cc:42:37: error: a function-definition is not allowed here before '{' token
   42 | int DaysOfMonth(int year, int month){
      |                                     ^
foo.cc:52:45: error: a function-definition is not allowed here before '{' token
   52 | int WeekdayOfTheFirstDay(int year,int month){
      |                                             ^
foo.cc:62:11: error: a function-definition is not allowed here before '{' token
   62 | int main(){
      |           ^

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