Problem: You are given n words, each of which consists of lowercase alphabet letters. Each word contains at least one vowel. You are going to choose some of the given words and make as many beautiful lyrics as possible.

Each lyric consists of two lines. Each line consists of two words separated by whitespace. 

A lyric is beautiful if and only if it satisfies all conditions below. 

  * The number of vowels in the first word of the first line is the same as the number of vowels in the first word of the second line. 
  * The number of vowels in the second word of the first line is the same as the number of vowels in the second word of the second line. 
  * The last vowel of the first line is the same as the last vowel of the second line. Note that there may be consonants after the vowel. 



Also, letters "a", "e", "o", "i", and "u" are vowels. Note that "y" is never vowel.

For example of a beautiful lyric, 

"hello hellooowww" 

"whatsup yowowowow" 

is a beautiful lyric because there are two vowels each in "hello" and "whatsup", four vowels each in "hellooowww" and "yowowowow" (keep in mind that "y" is not a vowel), and the last vowel of each line is "o".

For example of a not beautiful lyric, 

"hey man"

"iam mcdic" 

is not a beautiful lyric because "hey" and "iam" don't have same number of vowels and the last vowels of two lines are different ("a" in the first and "i" in the second).

How many beautiful lyrics can you write from given words? Note that you cannot use a word more times than it is given to you. For example, if a word is given three times, you can use it at most three times.

Input

The first line contains single integer n (1 ≤ n ≤ 10^{5}) — the number of words.

The i-th of the next n lines contains string s_{i} consisting lowercase alphabet letters — the i-th word. It is guaranteed that the sum of the total word length is equal or less than 10^{6}. Each word contains at least one vowel.

Output

In the first line, print m — the number of maximum possible beautiful lyrics.

In next 2m lines, print m beautiful lyrics (two lines per lyric).

If there are multiple answers, print any.

Examples

Input


14
wow
this
is
the
first
mcdics
codeforces
round
hooray
i
am
proud
about
that


Output


3
about proud
hooray round
wow first
this is
i that
mcdics am


Input


7
arsijo
suggested
the
idea
for
this
problem


Output


0


Input


4
same
same
same
differ


Output


1
same differ
same same

Note

In the first example, those beautiful lyrics are one of the possible answers. Let's look at the first lyric on the sample output of the first example. "about proud hooray round" forms a beautiful lyric because "about" and "hooray" have same number of vowels, "proud" and "round" have same number of vowels, and both lines have same last vowel. On the other hand, you cannot form any beautiful lyric with the word "codeforces".

In the second example, you cannot form any beautiful lyric from given words.

In the third example, you can use the word "same" up to three times.

Solution (in JAVA):

Solution:


import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.math.BigInteger;
import java.nio.charset.Charset;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Deque;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.stream.Collectors;

public class CFContest {
    public static void main(String[] args) throws Exception {
        boolean local = System.getProperty("ONLINE_JUDGE") == null;
        boolean async = false;

        Charset charset = Charset.forName("ascii");

        FastIO io = local ? new FastIO(new FileInputStream("D:\\DATABASE\\TESTCASE\\Code.in"), System.out, charset) : new FastIO(System.in, System.out, charset);
        Task task = new Task(io, new Debug(local));

        if (async) {
            Thread t = new Thread(null, task, "dalt", 1 << 27);
            t.setPriority(Thread.MAX_PRIORITY);
            t.start();
            t.join();
        } else {
            task.run();
        }

        if (local) {
            io.cache.append("\n\n--memory -- \n" + ((Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()) >> 20) + "M");
        }

        io.flush();
    }

    public static class Task implements Runnable {
        final FastIO io;
        final Debug debug;
        int inf = (int) 1e9 + 2;
        MathUtils.Modular modular = new MathUtils.Modular(998244353);

        public Task(FastIO io, Debug debug) {
            this.io = io;
            this.debug = debug;
        }

        @Override
        public void run() {
            solve();
        }

        public void solve() {
            int n = io.readInt();
            int limit = 1000000;
            Map<Integer, String> map = new HashMap<>();
            Deque<String[]> pairs = new ArrayDeque<>();
            for (int i = 0; i <= limit; i++) {
                String s = io.readString();
                int vowel = -1;
                int cnt = 0;
                for (int j = s.length() - 1; j >= 0; j--) {
                    char c = s.charAt(j);
                    if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') {
                        if (vowel == -1) {
                            vowel = c;
                        }
                        cnt++;
                    }
                }
                if (vowel == -1) {
                    continue;
                }
                int merge = cnt + vowel * limit;
                if (!map.containsKey(merge)) {
                    map.put(merge, s);
                } else {
                    pairs.add(new String[]{s, map.remove(merge)});
                }
            }

            Map<Integer, List<String>> equalLengthMap = new HashMap<>();
            for (Map.Entry<Integer, String> entry : map.entrySet()) {
                int key = entry.getKey() % limit;
                if (!equalLengthMap.containsKey(key)) {
                    equalLengthMap.put(key, new ArrayList<>(1));
                }
                equalLengthMap.get(key).add(entry.getValue());
            }

            List<String[]> ans = new ArrayList<>();
            for (List<String> list : equalLengthMap.values()) {
                for (int i = 1, until = list.size(); i < until && !pairs.isEmpty(); i += 2) {
                    String[] head = pairs.removeFirst();
                    ans.add(new String[]{list.get(i), head[0], list.get(i - 1), head[1]});
                }
            }
            while (pairs.size() >= 2) {
                String[] head = pairs.removeFirst();
                String[] tail = pairs.removeLast();
                ans.add(new String[]{head[0], tail[0], head[1], tail[1]});
            }

            io.cache.append(ans.size()).append('\n');
            for (String[] a : ans) {
                io.cache.append(a[0]).append(' ').append(a[1])
                        .append('\n').append(a[2]).append(' ').append(a[3]).append('\n');
            }
        }
    }


    public static class MathUtils {
        private static Random random = new Random(123456789);

        public static class ExtLucasFactorial {
            int exp;
            int fact;
            int p;
            int pc;
            Modular modular;
            Power power;
            ExtGCD extGCD = new ExtGCD();
            int[] g;

            /**
             * O(pc)
             *
             * @param p  the prime
             * @param pc p^c
             * @param g  buffer
             */
            public ExtLucasFactorial(int p, int pc, int[] g) {
                this.p = p;
                this.pc = pc;
                this.g = g;
                modular = new Modular(pc);
                power = new Power(modular);
                g[0] = 1;
                g[1] = 1;
                for (int i = 2; i <= pc; i++) {
                    if (i % p == 0) {
                        g[i] = g[i - 1];
                    } else {
                        g[i] = modular.mul(g[i - 1], i);
                    }
                }
            }

            /**
             * return m! (mod pc) without any factor which is multiple of p.
             * <br>
             * O(\log_2^2{m})
             */
            private int fact(long m) {
                fact = 1;
                exp = 0;
                while (m > 1) {
                    exp += m / p;
                    fact = modular.mul(fact, power.pow(g[pc], m / pc));
                    fact = modular.mul(fact, g[(int) (m % pc)]);
                    m /= p;
                }
                return fact;
            }

            /**
             * Find C(m,n), it means choose n elements from a set whose size is m.
             * <br>
             * O(\log_2^2{m})
             */
            public int composite(long m, long n) {
                int v = fact(m);
                int e = exp;
                extGCD.extgcd(fact(n), pc);
                v = modular.mul(v, modular.valueOf(extGCD.getX()));
                e -= exp;
                extGCD.extgcd(fact(m - n), pc);
                v = modular.mul(v, modular.valueOf(extGCD.getX()));
                e -= exp;
                v = modular.mul(v, power.pow(p, e));
                return v;
            }
        }

        /**
         * 扩展卢卡斯算法
         */
        public static class ExtLucas {
            PollardRho pr = new PollardRho();
            Map<Integer, ExtLucasFactorial> factorialMap = new HashMap();

            public ExtLucas(int p) {
                Map<Integer, Integer> factors = pr.findAllFactors(p);
                for (Map.Entry<Integer, Integer> entry : factors.entrySet()) {
                    factorialMap.put(entry.getValue(), new ExtLucasFactorial(entry.getKey(), entry.getValue(), new int[entry.getValue() + 1]));
                }
            }

            /**
             * Get C(m, n) % p
             */
            public int composite(long m, long n) {
                ExtCRT extCRT = new ExtCRT();
                for (Map.Entry<Integer, ExtLucasFactorial> entry : factorialMap.entrySet()) {
                    extCRT.add(entry.getValue().composite(m, n), entry.getKey());
                }
                return (int) extCRT.r;
            }
        }

        /**
         * 扩展卢卡斯算法
         */
        public static class LongExtLucas {
            LongPollardRho pr = new LongPollardRho();
            Map<Integer, ExtLucasFactorial> factorialMap = new HashMap();

            public LongExtLucas(long p) {
                Map<Long, Long> factors = pr.findAllFactors(p);
                for (Map.Entry<Long, Long> entry : factors.entrySet()) {
                    factorialMap.put(entry.getValue().intValue(), new ExtLucasFactorial(entry.getKey().intValue(), entry.getValue().intValue(), new int[entry.getValue().intValue() + 1]));
                }
            }

            /**
             * Get C(m, n) % p
             */
            public int composite(long m, long n) {
                ExtCRT extCRT = new ExtCRT();
                for (Map.Entry<Integer, ExtLucasFactorial> entry : factorialMap.entrySet()) {
                    extCRT.add(entry.getValue().composite(m, n), entry.getKey());
                }
                return (int) extCRT.r;
            }
        }

        /**
         * 扩展欧几里得
         */
        public static class ExtGCD extends Gcd {
            private long x;
            private long y;

            public long getX() {
                return x;
            }

            public long getY() {
                return y;
            }

            /**
             * Get g = Gcd(a, b) and find a way to set x and y to match ax+by=g
             */
            public long extgcd(long a, long b) {
                if (a >= b) {
                    return extgcd0(a, b);
                } else {
                    long g = extgcd0(b, a);
                    long tmp = x;
                    x = y;
                    y = tmp;
                    return g;
                }
            }

            private long extgcd0(long a, long b) {
                if (b == 0) {
                    x = 1;
                    y = 0;
                    return a;
                }
                long g = extgcd0(b, a % b);
                long n = x;
                long m = y;
                x = m;
                y = n - m * (a / b);
                return g;
            }
        }

        public static class Gcd {
            public long gcd(long a, long b) {
                return a >= b ? gcd0(a, b) : gcd0(b, a);
            }

            private long gcd0(long a, long b) {
                return b == 0 ? a : gcd0(b, a % b);
            }

            public int gcd(int a, int b) {
                return a >= b ? gcd0(a, b) : gcd0(b, a);
            }

            private int gcd0(int a, int b) {
                return b == 0 ? a : gcd0(b, a % b);
            }
        }

        /**
         * 欧拉筛
         */
        public static class EulerSieve {
            int[] primes;
            boolean[] isComp;
            int primeLength;

            public EulerSieve(int limit) {
                isComp = new boolean[limit + 1];
                primes = new int[limit + 1];
                primeLength = 0;
                for (int i = 2; i <= limit; i++) {
                    if (!isComp[i]) {
                        primes[primeLength++] = i;
                    }
                    for (int j = 0, until = limit / i; j < primeLength && primes[j] <= until; j++) {
                        int pi = primes[j] * i;
                        isComp[pi] = true;
                        if (i % primes[j] == 0) {
                            break;
                        }
                    }
                }
            }
        }

        /**
         * 模运算
         */
        public static class Modular {
            final int m;

            public Modular(int m) {
                this.m = m;
            }

            public int valueOf(int x) {
                x %= m;
                if (x < 0) {
                    x += m;
                }
                return x;
            }

            public int valueOf(long x) {
                x %= m;
                if (x < 0) {
                    x += m;
                }
                return (int) x;
            }

            public int mul(int x, int y) {
                return valueOf((long) x * y);
            }

            public int plus(int x, int y) {
                return valueOf(x + y);
            }

            @Override
            public String toString() {
                return "mod " + m;
            }
        }

        /**
         * 位运算
         */
        public static class BitOperator {
            public int bitAt(int x, int i) {
                return (x >> i) & 1;
            }

            public int bitAt(long x, int i) {
                return (int) ((x >> i) & 1);
            }

            public int setBit(int x, int i, boolean v) {
                if (v) {
                    x |= 1 << i;
                } else {
                    x &= ~(1 << i);
                }
                return x;
            }

            public long setBit(long x, int i, boolean v) {
                if (v) {
                    x |= 1L << i;
                } else {
                    x &= ~(1L << i);
                }
                return x;
            }
        }

        /**
         * 幂运算
         */
        public static class Power {
            final Modular modular;

            public Power(Modular modular) {
                this.modular = modular;
            }

            public int pow(int x, long n) {
                if (n == 0) {
                    return 1;
                }
                long r = pow(x, n >> 1);
                r = modular.valueOf(r * r);
                if ((n & 1) == 1) {
                    r = modular.valueOf(r * x);
                }
                return (int) r;
            }

            public int inverse(int x) {
                return pow(x, modular.m - 2);
            }

            public int pow2(int x) {
                return x * x;
            }

            public long pow2(long x) {
                return x * x;
            }

            public double pow2(double x) {
                return x * x;
            }
        }

        /**
         * 对数
         */
        public static class Log2 {
            public int ceilLog(int x) {
                return 32 - Integer.numberOfLeadingZeros(x - 1);
            }

            public int floorLog(int x) {
                return 31 - Integer.numberOfLeadingZeros(x);
            }

            public int ceilLog(long x) {
                return 64 - Long.numberOfLeadingZeros(x - 1);
            }

            public int floorLog(long x) {
                return 63 - Long.numberOfLeadingZeros(x);
            }
        }

        /**
         * 乘法逆元
         */
        public static class InverseNumber {
            int[] inv;

            public InverseNumber(int[] inv, int limit, Modular modular) {
                this.inv = inv;
                inv[1] = 1;
                int p = modular.m;
                for (int i = 2; i <= limit; i++) {
                    int k = p / i;
                    int r = p % i;
                    inv[i] = modular.mul(-k, inv[r]);
                }
            }

            public InverseNumber(int limit, Modular modular) {
                this(new int[limit + 1], limit, modular);
            }
        }

        /**
         * 排列
         */
        public static class Factorial {
            int[] fact;
            int[] inv;

            public Factorial(int[] fact, int[] inv, InverseNumber in, int limit, Modular modular) {
                this.fact = fact;
                this.inv = inv;
                fact[0] = inv[0] = 1;
                for (int i = 1; i <= limit; i++) {
                    fact[i] = modular.mul(fact[i - 1], i);
                    inv[i] = modular.mul(inv[i - 1], in.inv[i]);
                }
            }

            public Factorial(int limit, Modular modular) {
                this(new int[limit + 1], new int[limit + 1], new InverseNumber(limit, modular), limit, modular);
            }
        }

        /**
         * 组合
         */
        public static class Composite {
            final Factorial factorial;
            final Modular modular;

            public Composite(Factorial factorial, Modular modular) {
                this.factorial = factorial;
                this.modular = modular;
            }

            public Composite(int limit, Modular modular) {
                this(new Factorial(limit, modular), modular);
            }

            public int composite(int m, int n) {
                if (n > m) {
                    return 0;
                }
                return modular.mul(modular.mul(factorial.fact[m], factorial.inv[n]), factorial.inv[m - n]);
            }
        }

        /**
         * 大素数测试
         */
        public static class MillerRabin {
            Modular modular;
            Power power;

            /**
             * 判断n是否是素数
             */
            public boolean mr(int n, int s) {
                if (n == 2) {
                    return true;
                }
                if (n % 2 == 0) {
                    return false;
                }
                modular = new Modular(n);
                power = new Power(modular);
                for (int i = 0; i < s; i++) {
                    int x = random.nextInt(n - 2) + 2;
                    if (!mr0(x, n)) {
                        return false;
                    }
                }
                return true;
            }

            private boolean mr0(int x, int n) {
                int exp = n - 1;
                while (true) {
                    int y = power.pow(x, exp);
                    if (y != 1 && y != n - 1) {
                        return false;
                    }
                    if (y != 1 || exp % 2 == 1) {
                        break;
                    }
                    exp = exp / 2;
                }
                return true;
            }
        }


        public static class LongModular {
            final long m;

            public LongModular(long m) {
                this.m = m;
            }

            public long mul(long a, long b) {
                return b == 0 ? 0 : ((mul(a, b >> 1) << 1) % m + a * (b & 1)) % m;
            }

            public long plus(long a, long b) {
                return valueOf(a + b);
            }

            public long valueOf(long a) {
                a %= m;
                if (a < 0) {
                    a += m;
                }
                return a;
            }
        }

        public static class LongPower {
            final LongModular modular;

            public LongPower(LongModular modular) {
                this.modular = modular;
            }

            long pow(long x, long n) {
                if (n == 0) {
                    return 1;
                }
                long r = pow(x, n >> 1);
                r = modular.mul(r, r);
                if ((n & 1) == 1) {
                    r = modular.mul(r, x);
                }
                return r;
            }

            long inverse(long x) {
                return pow(x, modular.m - 2);
            }
        }

        /**
         * 大素数测试
         */
        public static class LongMillerRabin {
            LongModular modular;
            LongPower power;

            /**
             * 判断n是否是素数
             */
            public boolean mr(long n, int s) {
                if (n == 2) {
                    return true;
                }
                if (n % 2 == 0) {
                    return false;
                }
                modular = new LongModular(n);
                power = new LongPower(modular);
                for (int i = 0; i < s; i++) {
                    long x = (long) (random.nextDouble() * (n - 2) + 2);
                    if (!mr0(x, n)) {
                        return false;
                    }
                }
                return true;
            }

            private boolean mr0(long x, long n) {
                long exp = n - 1;
                while (true) {
                    long y = power.pow(x, exp);
                    if (y != 1 && y != n - 1) {
                        return false;
                    }
                    if (y != 1 || exp % 2 == 1) {
                        break;
                    }
                    exp = exp / 2;
                }
                return true;
            }
        }

        public static class LongPollardRho {
            LongMillerRabin mr = new LongMillerRabin();
            Gcd gcd = new Gcd();
            LongModular modular;

            /**
             * Find a factor of n, if n is returned, it means n is 1 or a prime
             */
            public long findFactor(long n) {
                if (mr.mr(n, 3)) {
                    return n;
                }
                modular = new LongModular(n);
                while (true) {
                    long f = findFactor0((long) (random.nextDouble() * n), (long) (random.nextDouble() * n), n);
                    if (f != -1) {
                        return f;
                    }
                }
            }

            private long findFactor0(long x, long c, long n) {
                long xi = x;
                long xj = x;
                int j = 2;
                int i = 1;
                while (i < n) {
                    i++;
                    xi = modular.plus(modular.mul(xi, xi), c);
                    long g = gcd.gcd(n, Math.abs(xi - xj));
                    if (g != 1 && g != n) {
                        return g;
                    }
                    if (i == j) {
                        j = j << 1;
                        xj = xi;
                    }
                }
                return -1;
            }

            /**
             * Find the representation of n=p1^c1 * p2^c2 * ... * pm ^ cm.
             * <br>
             * The returned map contained such entries: pi -> pi^ci
             */
            public Map<Long, Long> findAllFactors(long n) {
                Map<Long, Long> map = new HashMap();
                findAllFactors(map, n);
                return map;
            }

            private void findAllFactors(Map<Long, Long> map, long n) {
                if (n == 1) {
                    return;
                }
                long f = findFactor(n);
                if (f == n) {
                    Long value = map.get(f);
                    if (value == null) {
                        value = 1L;
                    }
                    map.put(f, value * f);
                    return;
                }
                findAllFactors(map, f);
                findAllFactors(map, n / f);
            }

        }

        /**
         * 扩展中国余数定理
         */
        public static class ExtCRT {
            /**
             * remainder
             */
            long r;
            /**
             * modulus
             */
            long m;
            ExtGCD gcd = new ExtGCD();

            public ExtCRT() {
                r = 0;
                m = 1;
            }

            /**
             * Add a new condition: x % m = r
             */
            public boolean add(long r, long m) {
                long m1 = this.m;
                long x1 = this.r;
                long m2 = m;
                long x2 = ((r % m) + m) % m;
                long g = gcd.extgcd(m1, m2);
                long a = gcd.getX();
                if ((x2 - x1) % g != 0) {
                    return false;
                }
                this.m = m1 / g * m2;
                this.r = BigInteger.valueOf(a).multiply(BigInteger.valueOf((x2 - x1) / g))
                        .multiply(BigInteger.valueOf(m1)).add(BigInteger.valueOf(x1))
                        .mod(BigInteger.valueOf(this.m)).longValue();
                return true;
            }
        }

        /**
         * 卢卡斯定理
         */
        public static class Lucas {
            private final Composite composite;
            private int modulus;

            public Lucas(Composite composite) {
                this.composite = composite;
                this.modulus = composite.modular.m;
            }

            public int composite(long m, long n) {
                if (n == 0) {
                    return 1;
                }
                return composite.modular.mul(composite.composite((int) (m % modulus), (int) (n % modulus)),
                        composite(m / modulus, n / modulus));
            }
        }

        /**
         * 因式分解
         */
        public static class PollardRho {
            MillerRabin mr = new MillerRabin();
            Gcd gcd = new Gcd();
            Random random = new Random(123456789);

            public int findFactor(int n) {
                if (mr.mr(n, 10)) {
                    return n;
                }
                while (true) {
                    int f = findFactor0(random.nextInt(n), random.nextInt(n), n);
                    if (f != -1) {
                        return f;
                    }
                }
            }

            public Map<Integer, Integer> findAllFactors(int n) {
                Map<Integer, Integer> map = new HashMap();
                findAllFactors(map, n);
                return map;
            }

            private void findAllFactors(Map<Integer, Integer> map, int n) {
                if (n == 1) {
                    return;
                }
                int f = findFactor(n);
                if (f == n) {
                    Integer value = map.get(f);
                    if (value == null) {
                        value = 1;
                    }
                    map.put(f, value * f);
                    return;
                }
                findAllFactors(map, f);
                findAllFactors(map, n / f);
            }

            private int findFactor0(int x, int c, int n) {
                int xi = x;
                int xj = x;
                int j = 2;
                int i = 1;
                while (i < n) {
                    i++;
                    xi = (int) ((long) xi * xi + c) % n;
                    int g = gcd.gcd(n, Math.abs(xi - xj));
                    if (g != 1 && g != n) {
                        return g;
                    }
                    if (i == j) {
                        j = j << 1;
                        xj = xi;
                    }
                }
                return -1;
            }
        }
    }

    public static class FastIO {
        public final StringBuilder cache = new StringBuilder();
        private final InputStream is;
        private final OutputStream os;
        private final Charset charset;
        private StringBuilder defaultStringBuf = new StringBuilder(1 << 8);
        private byte[] buf = new byte[1 << 13];
        private int bufLen;
        private int bufOffset;
        private int next;

        public FastIO(InputStream is, OutputStream os, Charset charset) {
            this.is = is;
            this.os = os;
            this.charset = charset;
        }

        public FastIO(InputStream is, OutputStream os) {
            this(is, os, Charset.forName("ascii"));
        }

        private int read() {
            while (bufLen == bufOffset) {
                bufOffset = 0;
                try {
                    bufLen = is.read(buf);
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
                if (bufLen == -1) {
                    return -1;
                }
            }
            return buf[bufOffset++];
        }

        public void skipBlank() {
            while (next >= 0 && next <= 32) {
                next = read();
            }
        }

        public int readInt() {
            int sign = 1;

            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+' ? 1 : -1;
                next = read();
            }

            int val = 0;
            if (sign == 1) {
                while (next >= '0' && next <= '9') {
                    val = val * 10 + next - '0';
                    next = read();
                }
            } else {
                while (next >= '0' && next <= '9') {
                    val = val * 10 - next + '0';
                    next = read();
                }
            }

            return val;
        }

        public long readLong() {
            int sign = 1;

            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+' ? 1 : -1;
                next = read();
            }

            long val = 0;
            if (sign == 1) {
                while (next >= '0' && next <= '9') {
                    val = val * 10 + next - '0';
                    next = read();
                }
            } else {
                while (next >= '0' && next <= '9') {
                    val = val * 10 - next + '0';
                    next = read();
                }
            }

            return val;
        }

        public double readDouble() {
            boolean sign = true;
            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+';
                next = read();
            }

            long val = 0;
            while (next >= '0' && next <= '9') {
                val = val * 10 + next - '0';
                next = read();
            }
            if (next != '.') {
                return sign ? val : -val;
            }
            next = read();
            long radix = 1;
            long point = 0;
            while (next >= '0' && next <= '9') {
                point = point * 10 + next - '0';
                radix = radix * 10;
                next = read();
            }
            double result = val + (double) point / radix;
            return sign ? result : -result;
        }

        public String readString(StringBuilder builder) {
            skipBlank();

            while (next > 32) {
                builder.append((char) next);
                next = read();
            }

            return builder.toString();
        }

        public String readString() {
            defaultStringBuf.setLength(0);
            return readString(defaultStringBuf);
        }

        public int readLine(char[] data, int offset) {
            int originalOffset = offset;
            while (next != -1 && next != '\n') {
                data[offset++] = (char) next;
                next = read();
            }
            return offset - originalOffset;
        }

        public int readString(char[] data, int offset) {
            skipBlank();

            int originalOffset = offset;
            while (next > 32) {
                data[offset++] = (char) next;
                next = read();
            }

            return offset - originalOffset;
        }

        public int readString(byte[] data, int offset) {
            skipBlank();

            int originalOffset = offset;
            while (next > 32) {
                data[offset++] = (byte) next;
                next = read();
            }

            return offset - originalOffset;
        }

        public char readChar() {
            skipBlank();
            char c = (char) next;
            next = read();
            return c;
        }

        public void flush() {
            try {
                os.write(cache.toString().getBytes(charset));
                os.flush();
                cache.setLength(0);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        public boolean hasMore() {
            skipBlank();
            return next != -1;
        }
    }

    public static class Debug {
        private boolean allowDebug;

        public Debug(boolean allowDebug) {
            this.allowDebug = allowDebug;
        }

        public void assertTrue(boolean flag) {
            if (!allowDebug) {
                return;
            }
            if (!flag) {
                fail();
            }
        }

        public void fail() {
            throw new RuntimeException();
        }

        public void assertFalse(boolean flag) {
            if (!allowDebug) {
                return;
            }
            if (flag) {
                fail();
            }
        }

        private void outputName(String name) {
            System.out.print(name + " = ");
        }

        public void debug(String name, int x) {
            if (!allowDebug) {
                return;
            }

            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, long x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, double x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, int[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, long[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, double[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, Object x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, Object... x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.deepToString(x));
        }
    }
}