#include <stdio.h> int main() { double price; int mouth, day, discount; double pay; scanf("%lf %d %d %d", &price, &mouth, &day, &discount); if(mouth == 11 && day == 11) { pay = price * 0.7; if(discount){ pay -= 50; } if(pay >= 0) { printf("%.2lf", pay); }else { print...