#include<cstring>
#include<iostream>
#define LEN 10
using namespace std;
char elem[LEN] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j' };
char result[LEN];
bool filled[LEN];
void permutation(int k, int n) {
    if (k == n) {
        for (int i = 0; i < n; i++) {
            cout << result[i] << " ";
 
        }
        cout << endl;
    } else {
        for (int i = 0; i < n; i++) {
            if (!filled[i]) {
                filled[i] = true;
                result[k] = elem[i];
                permutation(k + 1, n);
                filled[i] = false;
            }
        }
    }
}
int main() {
    memset(result, 0, sizeof(result));
    memset(filled, false, sizeof(filled));
    permutation(0, LEN);
    return 0;
}