#include <iostream> using namespace std; int main() { int year, mon, day; int data[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; while (cin >> year >> mon >> day) { int sum; for (int i = 0; i < mon - 1; i++) { sum = sum + data[i]; } if ((year % 400 == 0 || (year % ...