Polycarp has n different binary words. A word called binary if it contains only characters '0' and '1'. For example, these words are binary: "0001", "11", "0" and "0011100".

Polycarp wants to offer his set of n binary words to play a game "words". In this game, players name words and each next word (starting from the second) must start with the last character of the previous word. The first word can be any. For example, these sequence of words can be named during the game: "0101", "1", "10", "00", "00001".

Word reversal is the operation of reversing the order of the characters. For example, the word "0111" after the reversal becomes "1110", the word "11010" after the reversal becomes "01011".

Probably, Polycarp has such a set of words that there is no way to put them in the order correspondent to the game rules. In this situation, he wants to reverse some words from his set so that:

  * the final set of n words still contains different words (i.e. all words are unique); 
  * there is a way to put all words of the final set of words in the order so that the final sequence of n words is consistent with the game rules. 



Polycarp wants to reverse minimal number of words. Please, help him.

Input

The first line of the input contains one integer t (1 ≤ t ≤ 10^4) — the number of test cases in the input. Then t test cases follow.

The first line of a test case contains one integer n (1 ≤ n ≤ 2⋅10^5) — the number of words in the Polycarp's set. Next n lines contain these words. All of n words aren't empty and contains only characters '0' and '1'. The sum of word lengths doesn't exceed 4⋅10^6. All words are different.

Guaranteed, that the sum of n for all test cases in the input doesn't exceed 2⋅10^5. Also, guaranteed that the sum of word lengths for all test cases in the input doesn't exceed 4⋅10^6.

Output

Print answer for all of t test cases in the order they appear.

If there is no answer for the test case, print -1. Otherwise, the first line of the output should contain k (0 ≤ k ≤ n) — the minimal number of words in the set which should be reversed. The second line of the output should contain k distinct integers — the indexes of the words in the set which should be reversed. Words are numerated from 1 to n in the order they appear. If k=0 you can skip this line (or you can print an empty line). If there are many answers you can print any of them.

Example

Input


4
4
0001
1000
0011
0111
3
010
101
0
2
00000
00001
4
01
001
0001
00001


Output


1
3 
-1
0

2
1 2 
import java.io.*;
import java.util.*;

import static java.lang.Math.*;
import static java.util.Arrays.*;

public class cf1277d {

    public static void main(String[] args) throws IOException {
        int t = ri();
        while (t --> 0) {
            int n = ri(), cnt00 = 0, cnt11 = 0, ind01 = 0, ind10 = 0, map01[] = new int[n], map10[] = new int[n];
            char set[][] = new char[n][], set01[][] = new char[n][], set10[][] = new char[n][];
            List<Integer> ans = new ArrayList<>();
            Set<String> hash01 = new HashSet<>(), hash10 = new HashSet<>();
            for (int i = 0; i < n; ++i) {
                set[i] = rcha();
                if (set[i][0] == set[i][set[i].length - 1]) {
                    if (set[i][0] == '0') {
                        ++cnt00;
                    } else {
                        ++cnt11;
                    }
                } else if (set[i][0] == '0') {
                    map01[ind01] = i;
                    set01[ind01++] = set[i];
                    hash01.add(new String(set[i]));
                } else {
                    reverse(set[i]);
                    map10[ind10] = i;
                    set10[ind10++] = set[i];
                    hash10.add(new String(set[i]));
                }
            }
            if (cnt00 > 0 && cnt11 > 0 && cnt00 + cnt11 == n) {
                prln(-1);
            } else {
                if (ind01 > ind10) {
                    int diff = ind01 - ind10, ind = 0;
                    for (int i = 0; i < diff / 2; ++i) {
                        while (hash10.contains(new String(set01[ind]))) {
                            ++ind;
                        }
                        ans.add(map01[ind++] + 1);
                    }
                } else {
                    int diff = ind10 - ind01, ind = 0;
                    for (int i = 0; i < diff / 2; ++i) {
                        while (hash01.contains(new String(set10[ind]))) {
                            ++ind;
                        }
                        ans.add(map10[ind++] + 1);
                    }
                }
                prln(ans.size());
                prln(ans);
            }
        }
        close();
    }

    static BufferedReader __in = new BufferedReader(new InputStreamReader(System.in));
    static PrintWriter __out = new PrintWriter(new OutputStreamWriter(System.out));
    static StringTokenizer input;
    static Random __rand = new Random();

    // references
    // IBIG = 1e9 + 7
    // IMAX ~= 2e9
    // LMAX ~= 9e18
    
    // constants
    static final int IBIG = 1000000007;
    static final int IMAX = 2147483647;
    static final int IMIN = -2147483648;
    static final long LMAX = 9223372036854775807L;
    static final long LMIN = -9223372036854775808L;
    // math util
    static int minof(int a, int b, int c) {return min(a, min(b, c));}
    static int minof(int... x) {if(x.length == 1) return x[0]; if(x.length == 2) return min(x[0], x[1]); if(x.length == 3) return min(x[0], min(x[1], x[2])); int min = x[0]; for(int i = 1; i < x.length; ++i) if(x[i] < min) min = x[i]; return min;}
    static long minof(long a, long b, long c) {return min(a, min(b, c));}
    static long minof(long... x) {if(x.length == 1) return x[0]; if(x.length == 2) return min(x[0], x[1]); if(x.length == 3) return min(x[0], min(x[1], x[2])); long min = x[0]; for(int i = 1; i < x.length; ++i) if(x[i] < min) min = x[i]; return min;}
    static int maxof(int a, int b, int c) {return max(a, max(b, c));}
    static int maxof(int... x) {if(x.length == 1) return x[0]; if(x.length == 2) return max(x[0], x[1]); if(x.length == 3) return max(x[0], max(x[1], x[2])); int max = x[0]; for(int i = 1; i < x.length; ++i) if(x[i] > max) max = x[i]; return max;}
    static long maxof(long a, long b, long c) {return max(a, max(b, c));}
    static long maxof(long... x) {if(x.length == 1) return x[0]; if(x.length == 2) return max(x[0], x[1]); if(x.length == 3) return max(x[0], max(x[1], x[2])); long max = x[0]; for(int i = 1; i < x.length; ++i) if(x[i] > max) max = x[i]; return max;}
    static int powi(int a, int b) {if(a == 0) return 0; int ans = 1; while(b > 0) {if((b & 1) > 0) ans *= a; a *= a; b >>= 1;} return ans;}
    static long powl(long a, int b) {if(a == 0) return 0; long ans = 1; while(b > 0) {if((b & 1) > 0) ans *= a; a *= a; b >>= 1;} return ans;}
    static int fli(double d) {return (int)d;}
    static int cei(double d) {return (int)ceil(d);}
    static long fll(double d) {return (long)d;}
    static long cel(double d) {return (long)ceil(d);}
    static int gcf(int a, int b) {return b == 0 ? a : gcf(b, a % b);}
    static long gcf(long a, long b) {return b == 0 ? a : gcf(b, a % b);}
    static int randInt(int min, int max) {return __rand.nextInt(max - min + 1) + min;}
    static long hash(long x) {x += 0x9e3779b97f4a7c15L; x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9L; x = (x ^ (x >> 27)) * 0x94d049bb133111ebL; return x ^ (x >> 31);}
    // array util
    static void reverse(int[] a) {for(int i = 0, n = a.length, half = n / 2; i < half; ++i) {int swap = a[i]; a[i] = a[n - i - 1]; a[n - i - 1] = swap;}}
    static void reverse(long[] a) {for(int i = 0, n = a.length, half = n / 2; i < half; ++i) {long swap = a[i]; a[i] = a[n - i - 1]; a[n - i - 1] = swap;}}
    static void reverse(char[] a) {for(int i = 0, n = a.length, half = n / 2; i < half; ++i) {char swap = a[i]; a[i] = a[n - i - 1]; a[n - i - 1] = swap;}}
    static void shuffle(int[] a) {int n = a.length - 1; for(int i = 0; i < n; ++i) {int ind = randInt(i, n); int swap = a[i]; a[i] = a[ind]; a[ind] = swap;}}
    static void shuffle(long[] a) {int n = a.length - 1; for(int i = 0; i < n; ++i) {int ind = randInt(i, n); long swap = a[i]; a[i] = a[ind]; a[ind] = swap;}}
    static void rsort(int[] a) {shuffle(a); sort(a);}
    static void rsort(long[] a) {shuffle(a); sort(a);}
    static int[] copy(int[] a) {int[] ans = new int[a.length]; for(int i = 0; i < a.length; ++i) ans[i] = a[i]; return ans;}
    static long[] copy(long[] a) {long[] ans = new long[a.length]; for(int i = 0; i < a.length; ++i) ans[i] = a[i]; return ans;}
    static char[] copy(char[] a) {char[] ans = new char[a.length]; for(int i = 0; i < a.length; ++i) ans[i] = a[i]; return ans;}
    static int[] sorted(int[] a) {int[] ans = copy(a); sort(ans); return ans;}
    static long[] sorted(long[] a) {long[] ans = copy(a); sort(ans); return ans;}
    static int[] rsorted(int[] a) {int[] ans = copy(a); rsort(ans); return ans;}
    static long[] rsorted(long[] a) {long[] ans = copy(a); rsort(ans); return ans;}
    // graph util
    static List<List<Integer>> graph(int n) {List<List<Integer>> g = new ArrayList<>(); for(int i = 0; i < n; ++i) g.add(new ArrayList<>()); return g;}
    static List<List<Integer>> graph(List<List<Integer>> g, int m) throws IOException {for(int i = 0; i < m; ++i) connect(g, rni() - 1, ni() - 1); return g;}
    static List<List<Integer>> graph(int n, int m) throws IOException {return graph(graph(n), m);}
    static List<List<Integer>> dgraph(List<List<Integer>> g, int m) throws IOException {for(int i = 0; i < m; ++i) connecto(g, rni() - 1, ni() - 1); return g;}
    static List<List<Integer>> dgraph(List<List<Integer>> g, int n, int m) throws IOException {return dgraph(graph(n), m);}
    static List<Set<Integer>> sgraph(int n) {List<Set<Integer>> g = new ArrayList<>(); for(int i = 0; i < n; ++i) g.add(new HashSet<>()); return g;}
    static List<Set<Integer>> sgraph(List<Set<Integer>> g, int m) throws IOException {for(int i = 0; i < m; ++i) connect(g, rni() - 1, ni() - 1); return g;}
    static List<Set<Integer>> sgraph(int n, int m) throws IOException {return sgraph(sgraph(n), m);}
    static List<Set<Integer>> dsgraph(List<Set<Integer>> g, int m) throws IOException {for(int i = 0; i < m; ++i) connecto(g, rni() - 1, ni() - 1); return g;}
    static List<Set<Integer>> dsgraph(List<Set<Integer>> g, int n, int m) throws IOException {return dsgraph(sgraph(n), m);}
    static void connect(List<? extends Collection<Integer>> g, int u, int v) {g.get(u).add(v); g.get(v).add(u);}
    static void connecto(List<? extends Collection<Integer>> g, int u, int v) {g.get(u).add(v);}
    static void dconnect(List<? extends Collection<Integer>> g, int u, int v) {g.get(u).remove(v); g.get(v).remove(u);}
    static void dconnecto(List<? extends Collection<Integer>> g, int u, int v) {g.get(u).remove(v);}
    // input
    static void r() throws IOException {input = new StringTokenizer(__in.readLine());}
    static int ri() throws IOException {return Integer.parseInt(__in.readLine());}
    static long rl() throws IOException {return Long.parseLong(__in.readLine());}
    static int[] ria(int n) throws IOException {int[] a = new int[n]; input = new StringTokenizer(__in.readLine()); for(int i = 0; i < n; ++i) a[i] = Integer.parseInt(input.nextToken()); return a;}
    static int[] riam1(int n) throws IOException {int[] a = new int[n]; input = new StringTokenizer(__in.readLine()); for(int i = 0; i < n; ++i) a[i] = Integer.parseInt(input.nextToken()) - 1; return a;}
    static long[] rla(int n) throws IOException {long[] a = new long[n]; input = new StringTokenizer(__in.readLine()); for(int i = 0; i < n; ++i) a[i] = Long.parseLong(input.nextToken()); return a;}
    static char[] rcha() throws IOException {return __in.readLine().toCharArray();}
    static String rline() throws IOException {return __in.readLine();}
    static int rni() throws IOException {input = new StringTokenizer(__in.readLine()); return Integer.parseInt(input.nextToken());}
    static int ni() {return Integer.parseInt(input.nextToken());}
    static long rnl() throws IOException {input = new StringTokenizer(__in.readLine()); return Long.parseLong(input.nextToken());}
    static long nl() {return Long.parseLong(input.nextToken());}
    // output
    static void pr(int i) {__out.print(i);}
    static void prln(int i) {__out.println(i);}
    static void pr(long l) {__out.print(l);}
    static void prln(long l) {__out.println(l);}
    static void pr(double d) {__out.print(d);}
    static void prln(double d) {__out.println(d);}
    static void pr(char c) {__out.print(c);}
    static void prln(char c) {__out.println(c);}
    static void pr(char[] s) {__out.print(new String(s));}
    static void prln(char[] s) {__out.println(new String(s));}
    static void pr(String s) {__out.print(s);}
    static void prln(String s) {__out.println(s);}
    static void pr(Object o) {__out.print(o);}
    static void prln(Object o) {__out.println(o);}
    static void prln() {__out.println();}
    static void pryes() {__out.println("yes");}
    static void pry() {__out.println("Yes");}
    static void prY() {__out.println("YES");}
    static void prno() {__out.println("no");}
    static void prn() {__out.println("No");}
    static void prN() {__out.println("NO");}
    static void pryesno(boolean b) {__out.println(b ? "yes" : "no");};
    static void pryn(boolean b) {__out.println(b ? "Yes" : "No");}
    static void prYN(boolean b) {__out.println(b ? "YES" : "NO");}
    static void prln(int... a) {for(int i = 0, len = a.length - 1; i < len; __out.print(a[i]), __out.print(' '), ++i); __out.println(a[a.length - 1]);}
    static void prln(long... a) {for(int i = 0, len = a.length - 1; i < len; __out.print(a[i]), __out.print(' '), ++i); __out.println(a[a.length - 1]);}
    static <T> void prln(Collection<T> c) {int n = c.size() - 1; Iterator<T> iter = c.iterator(); for(int i = 0; i < n; __out.print(iter.next()), __out.print(' '), ++i); if(n >= 0) __out.println(iter.next()); else __out.println();}
    static void h() {__out.println("hlfd");}
    static void flush() {__out.flush();}
    static void close() {__out.close();}
}