#include <stdio.h>

#define N 20

int data[N];
int n;

void subsets() {
    int i;
    for (i=0;i<data[0];i++)
        printf("%d ", data[i + 1]);
    if (data[0])
        printf("\n");

    for (i=data[data[0]] + 1;i<=n;i++) {
        data[++data[0]] = i;
        subsets();
        data[data[0]] = 0;
        --data[0];
    }
}

void subsetsk(int k) {
    int i;

    for (i=1;i<=k;i++) {
        printf("%d ", data[i]);
    }
    printf("\n");

    for (i = data[k] + 1; i <= n; i++) {
        data[k + 1] = i;
        subsetsk(k + 1);
    }
}

void subsetsbin() {
    int i, j;
    for (i=1;i<(1 << n);i++) {
        for (j=0;j<n;j++) {
            if (i & (1 << j)) {
                printf("%d ", j + 1);
            }
        }
        printf("\n");
    }
}

int main(void) {
    //scanf("%d", &n);
    n = 3;
    freopen("submultimi.in","r",stdin);
    freopen("submultimi.out","w",stdout);
    data[0] = 0;
    subsets();
    //subsetsbin();
    //subsetsk(0);
    return 0;
}