#include <iostream>using namespace std;bool isLeap(int year) { return (year % 4 == 0 && year % 100!= 0) || year % 400 == 0;}int main() { int year, month, day; cin >> year >> month >> day; int days[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; if (isLeap(yea...