#include <bits/stdc++.h> using namespace std; int day1[13]={0,31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; int day2[13]={0,31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; bool isvalid(int year,int mounth,int day){ if(year%400==0||(year%4==0&&year%100!=0)){ if(mounth<=12&&am...