#include <stdio.h> int Year(int y) { if(y%4==0&&y%100!=0||y%400==0) { return 1; } else return 0; } int Date(int y,int m) { int day[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}; int date=day[m]; if(Year(y)&&m==2) { date+=1; } return date;...