#include <stdio.h>
 
int is_uruu(int year){
	if(year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)){
		return 1;
	}
	return 0;
}
 
int maxday_of_month(int y, int m){
	if(m==1 || m==3 || m==5 || m==7 || m==8 || m==10 || m==12){
		return 31;
	}
	else if(m==4 || m==6 || m==9 || m==11){
		return 30;
	}
	else if(m == 2 && is_uruu(y) == 1){
		return 29;
	}
	else{
		return 28;
	}
}
 
int main(void) {
	int y=200,m=6;
	printf("%d日",maxday_of_month(y,m));
	return 0;
}
 

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