Problem: Grigory loves strings. Recently he found a metal strip on a loft. The strip had length n and consisted of letters "V" and "K". Unfortunately, rust has eaten some of the letters so that it's now impossible to understand which letter was written.

Grigory couldn't understand for a long time what these letters remind him of, so he became interested in the following question: if we put a letter "V" or "K" on each unreadable position, which values can the period of the resulting string be equal to?

A period of a string is such an integer d from 1 to the length of the string that if we put the string shifted by d positions to the right on itself, then all overlapping letters coincide. For example, 3 and 5 are periods of "VKKVK".

Input

There are several (at least one) test cases in the input. The first line contains single integer — the number of test cases.

There is an empty line before each test case. Each test case is described in two lines: the first line contains single integer n (1 ≤ n ≤ 5·105) — the length of the string, the second line contains the string of length n, consisting of letters "V", "K" and characters "?". The latter means the letter on its position is unreadable.

It is guaranteed that the sum of lengths among all test cases doesn't exceed 5·105.

For hacks you can only use tests with one test case.

Output

For each test case print two lines. In the first line print the number of possible periods after we replace each unreadable letter with "V" or "K". In the next line print all these values in increasing order.

Example

Input

3
 
5
V??VK
 
6
??????
 
4
?VK?


Output

2
3 5
6
1 2 3 4 5 6
3
2 3 4

Note

In the first test case from example we can obtain, for example, "VKKVK", which has periods 3 and 5.

In the second test case we can obtain "VVVVVV" which has all periods from 1 to 6.

In the third test case string "KVKV" has periods 2 and 4, and string "KVKK" has periods 3 and 4.

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;

public class E {

	boolean[] fast(String s) {
		int n = s.length();
		double[] vs = new double[n];
		double[] ks = new double[n];
		for (int i = 0; i < n; i++) {
			if (s.charAt(i) == 'V') {
				vs[i] = 1;
			} else if (s.charAt(i) == 'K') {
				ks[n - 1 - i] = 1;
			}
		}
		
		double[] prod = mult(vs, ks);
		boolean[] bad = new boolean[n + 1];
		for (int i = 0; i < 2 * n - 1; i++) {
			if (prod[i] > 0.5) {
//				System.err.println(i);
				bad[Math.abs(i - (n - 1))] = true;
			}
		}
		
//		System.err.println(Arrays.toString(bad));

		boolean[] ret = new boolean[n + 1];
		Arrays.fill(ret, true);
		for (int i = 1; i <= n; i++) {
			for (int j = i; j <= n; j += i) {
				if (bad[j]) {
					ret[i] = false;
				}
			}
		}
		
		return ret;
	}

	void submit() {
		int t = nextInt();
		while (t-- > 0) {
			int n = nextInt();
			String s = nextToken();
			boolean[] ans = fast(s);
			int cnt = 0;
			for (int i = 1; i <= n; i++) {
				if (ans[i]) {
					cnt++;
				}
			}
			out.println(cnt);
			for (int i = 1; i <= n; i++) {
				if (ans[i]) {
					out.print(i + " ");
				}
			}
			out.println();
		}
	}

	static int nextPowerOf2(int x) {
		return x == 1 ? 1 : Integer.highestOneBit(x - 1) << 1;
	}

	static class CompV {
		double[] re, im;

		void add(CompV o) {
			for (int i = 0; i < re.length; i++) {
				re[i] += o.re[i];
				im[i] += o.im[i];
			}
		}

		static CompV times(CompV a, CompV b) {
			double[] aRe = a.re;
			double[] aIm = a.im;
			double[] bRe = b.re;
			double[] bIm = b.im;
			double[] re = new double[aRe.length];
			double[] im = new double[aRe.length];

			for (int i = 0; i < aRe.length; i++) {
				re[i] = aRe[i] * bRe[i] - aIm[i] * bIm[i];
				im[i] = aRe[i] * bIm[i] + aIm[i] * bRe[i];
			}

			return new CompV(re, im);
		}

		/**
		 * @return a + bi
		 */
		static CompV packFFT(CompV a, CompV b) {
			double[] aRe = a.re;
			double[] aIm = a.im;
			double[] bRe = b.re;
			double[] bIm = b.im;
			double[] re = new double[aRe.length];
			double[] im = new double[aRe.length];
			for (int i = 0; i < aRe.length; i++) {
				re[i] = aRe[i] - bIm[i];
				im[i] = aIm[i] + bRe[i];
			}
			return new CompV(re, im);
		}

		/**
		 * for real-valued a and b restores FFT(a) and FFT(b) from FFT(a + bi)
		 */
		void unpackFFT(CompV a, CompV b) {
			int n = re.length;
			double[] aRe = a.re;
			double[] aIm = a.im;
			double[] bRe = b.re;
			double[] bIm = b.im;
			for (int i = 0; i < n; i++) {
				int j = i == 0 ? 0 : n - i;
				aRe[i] = (re[i] + re[j]) * 0.5;
				aIm[i] = (im[i] - im[j]) * 0.5;
				bRe[i] = (im[i] + im[j]) * 0.5;
				bIm[i] = (re[j] - re[i]) * 0.5;
			}
		}

		public CompV(double[] re, double[] im) {
			this.re = re;
			this.im = im;
		}

		public CompV(int len) {
			re = new double[len];
			im = new double[len];
		}
	}

	public static double[] mult(double[] a, double[] b) {
		int len = nextPowerOf2(a.length + b.length - 1);

		CompV abPack = new CompV(Arrays.copyOf(a, len), Arrays.copyOf(b, len));

		fft(abPack, false);

		CompV fa = new CompV(len);
		CompV fb = new CompV(len);
		abPack.unpackFFT(fa, fb);

		CompV fProd = CompV.times(fa, fb);

		fft(fProd, true);

		return fProd.re;
	}

	public static void fft(CompV v, boolean invert) {
		double[] a = v.re;
		double[] b = v.im;
		int n = a.length;
		int shift = 32 - Integer.numberOfTrailingZeros(n);
		prepareArrays(32 - shift);
		int[] rev = rev2D[32 - shift];
		// System.err.println(n + " " + shift);
		for (int i = 1; i < n; i++) {
			int j = rev[i];
			if (i < j) {
				double temp = a[i];
				a[i] = a[j];
				a[j] = temp;
				temp = b[i];
				b[i] = b[j];
				b[j] = temp;
			}
		}

		// this shit looks awkward
		double multInv = invert ? -1 : 1;

		for (int len = 2, row = 0; len <= n; len <<= 1, row++) {
			int halfLen = len >> 1;
			double[] multReArr = powRe[row];
			double[] multImArr = powIm[row];
			for (int i = 0; i < n; i += len) {
				int toJ = i + halfLen;

				for (int j1 = i, j2 = toJ, k = 0; k < halfLen; j1++, j2++, k++) {
					double uA = a[j1];
					double uB = b[j1];

					double multRe = multReArr[k];
					double multIm = multImArr[k] * multInv;

					double vA = a[j2] * multRe - b[j2] * multIm;
					double vB = a[j2] * multIm + b[j2] * multRe;
					a[j1] = uA + vA;
					b[j1] = uB + vB;
					a[j2] = uA - vA;
					b[j2] = uB - vB;
				}
			}
		}
		if (invert) {
			for (int i = 0; i < n; i++) {
				a[i] /= n;
				b[i] /= n;
			}
		}
	}

	static double[][] powRe = { { 1 } };
	static double[][] powIm = { { 0 } };
	static int[][] rev2D = {};

	static void prepareArrays(int n) {

		if (rev2D.length < n + 1) {
				rev2D = Arrays.copyOf(rev2D, n + 1);
		}

		if (rev2D[n] == null) {
			int[] tmp = rev2D[n] = new int[1 << n];
			for (int i = 0; i < (1 << n); i++) {
				tmp[i] = tmp[i >> 1] >> 1;
				if ((i & 1) == 1) {
					tmp[i] |= 1 << (n - 1);
				}
			}
		}

		int oldN = powRe.length;

		if (oldN >= n) {
			return;
		}

		powRe = Arrays.copyOf(powRe, n);
		powIm = Arrays.copyOf(powIm, n);

		for (int i = oldN; i < n; i++) {

			double angle = Math.PI / (1 << i);

			double multRe = Math.cos(angle);
			double multIm = Math.sin(angle);

			double[] toRe = powRe[i] = new double[1 << i];
			double[] toIm = powIm[i] = new double[1 << i];

			double[] fromRe = powRe[i - 1];
			double[] fromIm = powIm[i - 1];

			for (int j = 0; j < 1 << (i - 1); j++) {

				double re = fromRe[j];
				double im = fromIm[j];

				toRe[j << 1] = re;
				toIm[j << 1] = im;
				toRe[(j << 1) | 1] = re * multRe - im * multIm;
				toIm[(j << 1) | 1] = re * multIm + im * multRe;
			}

			// System.err.println(Arrays.toString(toRe));
			// System.err.println(Arrays.toString(toIm));
		}
	}

	void preCalc() {

	}

	void stress() {

	}

	void test() {

	}

	E() throws IOException {
		br = new BufferedReader(new InputStreamReader(System.in));
		out = new PrintWriter(System.out);
		preCalc();
		submit();
		// stress();
		// test();
		out.close();
	}

	static final Random rng = new Random();

	static int rand(int l, int r) {
		return l + rng.nextInt(r - l + 1);
	}

	public static void main(String[] args) throws IOException {
		new E();
	}

	BufferedReader br;
	PrintWriter out;
	StringTokenizer st;

	String nextToken() {
		while (st == null || !st.hasMoreTokens()) {
			try {
				st = new StringTokenizer(br.readLine());
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		}
		return st.nextToken();
	}

	String nextString() {
		try {
			return br.readLine();
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	int nextInt() {
		return Integer.parseInt(nextToken());
	}

	long nextLong() {
		return Long.parseLong(nextToken());
	}

	double nextDouble() {
		return Double.parseDouble(nextToken());
	}
}