#include <unistd.h>

int main() {
    char digit[3];
    digit[0] = '0';

    while (digit[0] <= '9') {
        digit[1] = '0';
        while (digit[1] <= '9') {
            digit[2] = '0';
            while (digit[2] <= '9') {
                if(digit[0] != digit[1]) {
                    if(digit[1] != digit[2]){
                        if(digit[0] != digit[2]){
                            write(1, digit, 3);
                            write(1, "\n", 1);
                        }
                    }
                }
                digit[2]++;
            }
            digit[1]++;
        }
        digit[0]++;
    }

    return 0;
}