#include <iostream>

int main() {

  // count down from 10 (C)
  for (int i = 10; i >= 0; i--) {
    printf("%d\n", i);
  }

  // count down from 10 (C++)
  for (int i = 10; i >= 0; i--) {
    std::cout << i << std::endl;
  }

  // all capital letters from A to Z (C).
  for (int i = 65; i <= 90; i++) {
    printf("%c\n", i);
  }

  // all capital letters from A to Z (C++).
  for (int i = 65; i <= 90; i++) {
    std::cout << char(i) << std::endl;
  }

  // all capital letters from A to Z (C++).
  for (char c{'A'}; c <= 'Z'; c++) {
    std::cout << c << std::endl;
  }

  return 0;
}