import java.util.Arrays; class SegmentTreeRSQ { public int M, H, N; public long[] st; public long[] plus; public SegmentTreeRSQ(int n) { N = n; M = Integer.highestOneBit(Math.max(N-1, 1))<<2; H = M>>>1; st = new long[M]; plus = new long[H]; } public SegmentTreeRSQ(int[] a) { N = a.length; M = Integer.highestOneBit(Math.max(N-1, 1))<<2; H = M>>>1; st = new long[M]; plus = new long[H]; for(int i = 0;i < N;i++){ st[H+i] = a[i]; } for(int i = (M>>1)-1;i >= 1;i--){ propagate(i); } } public void add(int pos, int v) { for(int i = H+pos;i >= 1;i >>>= 1){ st[i] += v; } } private void propagate(int i) { int count = H/Integer.highestOneBit(i); st[i] = st[2*i]+st[2*i+1]+plus[i]*count; } public void add(int l, int r, int v) { if(l < r)add(l, r, v, 0, H, 1); } private void add(int l, int r, int v, int cl, int cr, int cur) { if(cur >= H){ st[cur] += v; }else if(l <= cl && cr <= r){ plus[cur] += v; propagate(cur); }else{ int mid = cl+cr>>>1; if(cl < r && l < mid){ add(l, r, v, cl, mid, 2*cur); } if(mid < r && l < cr){ add(l, r, v, mid, cr, 2*cur+1); } propagate(cur); } } private long gsum; public long sum(int l, int r) { gsum = 0; sum(l, r, 0, H, 1); return gsum; } private void sum(int l, int r, int cl, int cr, int cur) { if(l <= cl && cr <= r){ gsum += st[cur]; }else{ int mid = cl+cr>>>1; if(cl < r && l < mid){ sum(l, r, cl, mid, 2*cur); } if(mid < r && l < cr){ sum(l, r, mid, cr, 2*cur+1); } gsum += plus[cur]*(Math.min(r,cr)-Math.max(l,cl)); } } } public class Main { private static void solve() { int n = ni(); int m = ni(); int[] out = new int[m]; int[] in = new int[m]; Arrays.fill(out, -1); Arrays.fill(in, -1); for (int i = 0; i < n; i ++) { int a = ni(); int b = ni(); if (a > b) { int tmp = a; a = b; b = tmp; } out[a] = i; in[b] = a; } SegmentTreeRSQ st = new SegmentTreeRSQ(m); long ret = 0; for (int i = 0; i < m; i ++) { if (out[i] >= 0) { st.add(i, 1); } else if (in[i] >= 0) { ret += st.sum(in[i] + 1, i); st.add(in[i], -1); } } System.out.println(ret); } public static void main(String[] args) { new Thread(null, new Runnable() { @Override public void run() { long start = System.currentTimeMillis(); String debug = args.length > 0 ? args[0] : null; if (debug != null) { try { is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug)); } catch (Exception e) { throw new RuntimeException(e); } } reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768); solve(); out.flush(); tr((System.currentTimeMillis() - start) + "ms"); } }, "", 64000000).start(); } private static java.io.InputStream is = System.in; private static java.io.PrintWriter out = new java.io.PrintWriter(System.out); private static java.util.StringTokenizer tokenizer = null; private static java.io.BufferedReader reader; public static String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new java.util.StringTokenizer(reader.readLine()); } catch (Exception e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } private static double nd() { return Double.parseDouble(next()); } private static long nl() { return Long.parseLong(next()); } private static int[] na(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = ni(); return a; } private static char[] ns() { return next().toCharArray(); } private static long[] nal(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nl(); return a; } private static int[][] ntable(int n, int m) { int[][] table = new int[n][m]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[i][j] = ni(); } } return table; } private static int[][] nlist(int n, int m) { int[][] table = new int[m][n]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[j][i] = ni(); } } return table; } private static int ni() { return Integer.parseInt(next()); } private static void tr(Object... o) { if (is != System.in) System.out.println(java.util.Arrays.deepToString(o)); } }