import java.io.IOException;
import java.io.InputStream;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        FastScanner fs = new FastScanner();
        int n = fs.nextInt();
        int[] a = new int[n];
        List<Integer> alist = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            a[i] = fs.nextInt();
            alist.add(a[i]);
        }
        /* まず，配列の要素に番号を振り直す*/
        alist.sort(Integer::compareTo);
        Map<Integer,Integer> map = new HashMap<>();
        for (int i = 0; i < n; i++) {
            map.put(alist.get(i),i);
        }
        for (int i = 0; i < n; i++) {
            a[i] = map.get(a[i]);
        }
        if (n == 1) {
            System.out.println(0);
        } else {
            int cnt = 0;
            for (int i = 1; i < n; i+=2) {
                if (a[i] % 2 == 0) {
                    cnt++;
                }
            }
            System.out.println(cnt);
        }


        /* 偶奇のミスマッチだけを見る
         * Odd番目に注目し，Odd番目にEvenの値があればカウント */

    }
}

class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }

    private int readByte() {
        if (hasNextByte()) return buffer[ptr++];
        else return -1;
    }

    private static boolean isPrintableChar(int c) {
        return 33 <= c && c <= 126;
    }

    public boolean hasNext() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
        return hasNextByte();
    }

    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }

    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }
}


Measured memory_bytes: 25380