#include <stdio.h> int main() { int a, b, c, d; for (a = 1; a <= 9; a++) { for (b = 0; b <= 9; b++) { for (c = 0; c <= 9; c++) { for (d = 0; d <= 9; d++) { if (d * 1000 + c * 100 + b * 10 + a == 9*(a * 1000 + b * 100 + c * 10 + d)) printf("%d%d%d%d\n", a, b, c, d); } } } } return 0; }