#include <bits/stdc++.h>
using namespace std;
const long long inf = 0x3f3f3f3f;
const long long mod = 1e9 + 7;
const double eps = 1e-6;
inline long long read() {
  long long f = 1, x = 0;
  char s = getchar();
  while (!isdigit(s)) {
    if (s == '-') f = -1;
    s = getchar();
  }
  while (isdigit(s)) {
    x = (x << 1) + (x << 3) + (s ^ 48);
    s = getchar();
  }
  return x * f;
}
long long n, m, a[200100];
double dp[1010][1010], ans;
signed main(void) {
  n = read(), m = read();
  for (long long i = 1; i <= n; i++) a[i] = read();
  for (long long i = 1; i <= n; i++)
    for (long long j = 1; j <= n; j++) dp[i][j] = a[i] > a[j];
  for (long long i = 1; i <= m; i++) {
    long long x = read(), y = read();
    for (long long j = 1; j <= n; j++) {
      dp[x][j] = dp[y][j] = 0.5 * (dp[x][j] + dp[y][j]);
      dp[j][x] = dp[j][y] = 1 - dp[x][j];
    }
    dp[x][y] = dp[y][x] = 0.5;
  }
  for (long long i = 1; i <= n; i++)
    for (long long j = i + 1; j <= n; j++) ans += dp[i][j];
  printf("%.8lf\n", ans);
  return 0;
}
