package contest210910; import java.io.*; import java.util.*; import java.util.function.IntUnaryOperator; import java.util.function.LongUnaryOperator; public class D { InputStream is; FastWriter out; String INPUT = ""; public void solve() { int n = ni(), Q = ni(); int[][] qs = new int[Q][]; for(int i = 0;i < Q;i++){ qs[i] = new int[]{ni()-1, ni()-1, ni()}; } Arrays.sort(qs, (x, y) -> -(x[2] - y[2])); SegmentTreeRMQ st = new SegmentTreeRMQ(n); LST lst = new LST(n); lst.setRange(n); for(int[] q : qs){ while(true){ int ne = lst.next(q[0]); if(ne != -1 && ne <= q[1]){ st.update(ne, q[2]); lst.unset(ne); }else{ break; } } if(st.min(q[0], q[1]+1) != q[2]){ out.println(-1); return; } } for(int i = 0;i < n;i++){ out.print(st.min(i, i+1) + " "); } out.println(); } public static class LST { public long[][] set; public int n; // public int size; public LST(int n) { this.n = n; int d = 1; for(int m = n;m > 1;m>>>=6, d++); set = new long[d][]; for(int i = 0, m = n>>>6;i < d;i++, m>>>=6){ set[i] = new long[m+1]; } // size = 0; } // [0,r) public LST setRange(int r) { for(int i = 0;i < set.length;i++, r=r+63>>>6){ for(int j = 0;j < r>>>6;j++){ set[i][j] = -1L; } if((r&63) != 0)set[i][r>>>6] |= (1L<= 0){ for(int i = 0;i < set.length;i++, r=r+63>>>6){ for(int j = 0;j < r+63>>>6;j++){ set[i][j] = 0; } if((r&63) != 0)set[i][r>>>6] &= ~((1L<= 0 && pos < n){ // if(!get(pos))size++; for(int i = 0;i < set.length;i++, pos>>>=6){ set[i][pos>>>6] |= 1L<= 0 && pos < n){ // if(get(pos))size--; for(int i = 0;i < set.length && (i == 0 || set[i-1][pos] == 0L);i++, pos>>>=6){ set[i][pos>>>6] &= ~(1L<= 0 && pos < n && set[0][pos>>>6]<<~pos<0; } public LST toggle(int pos) { return get(pos) ? unset(pos) : set(pos); } public int prev(int pos) { for(int i = 0;i < set.length && pos >= 0;i++, pos>>>=6, pos--){ int pre = prev(set[i][pos>>>6], pos&63); if(pre != -1){ pos = pos>>>6<<6|pre; while(i > 0)pos = pos<<6|63-Long.numberOfLeadingZeros(set[--i][pos]); return pos; } } return -1; } public int next(int pos) { for(int i = 0;i < set.length && pos>>>6 < set[i].length;i++, pos>>>=6, pos++){ int nex = next(set[i][pos>>>6], pos&63); if(nex != -1){ pos = pos>>>6<<6|nex; while(i > 0)pos = pos<<6|Long.numberOfTrailingZeros(set[--i][pos]); return pos; } } return -1; } private static int prev(long set, int n) { long h = set<<~n; if(h == 0L)return -1; return -Long.numberOfLeadingZeros(h)+n; } private static int next(long set, int n) { long h = set>>>n; if(h == 0L)return -1; return Long.numberOfTrailingZeros(h)+n; } @Override public String toString() { List list = new ArrayList(); for(int pos = next(0);pos != -1;pos = next(pos+1)){ list.add(pos); } return list.toString(); } } public static class SegmentTreeRMQ { public final int M, H, N; public int[] vals; public static final int I = Integer.MAX_VALUE; public SegmentTreeRMQ(int n) { N = n; M = Integer.highestOneBit(Math.max(N-1, 1))<<2; H = M>>>1; vals = new int[M]; Arrays.fill(vals, 0, M, 1000000000); } public SegmentTreeRMQ(int[] a) { this(a.length); for(int i = 0;i < N;i++){ vals[H+i] = a[i]; } // Arrays.fill(vals, H+N, M, I); for(int i = H-1;i >= 1;i--)propagate(i); } public void update(int pos, int x) { vals[H+pos] = x; for(int i = (H+pos)>>>1;i >= 1;i >>>= 1)propagate(i); } private void propagate(int i) { vals[i] = Math.min(vals[2*i], vals[2*i+1]); } public int min(int l, int r){ int min = I; if(l >= r)return min; l += H; r += H; for(;l < r;l>>>=1,r>>>=1){ if((l&1) == 1)min = Math.min(min, vals[l++]); if((r&1) == 1)min = Math.min(min, vals[--r]); } return min; } public int firstle(int l, int v) { if(l >= H)return -1; int cur = H+l; while(true){ if(vals[cur] <= v){ if(cur >= H)return cur-H; cur = 2*cur; }else{ cur++; if((cur&cur-1) == 0)return -1; if((cur&1)==0)cur>>>=1; } } } public int lastle(int l, int v) { if(l < 0)return -1; int cur = H+l; while(true){ if(vals[cur] <= v){ if(cur >= H)return cur-H; cur = 2*cur + 1; }else{ if((cur&cur-1) == 0)return -1; cur--; if((cur&1)==1)cur>>>=1; } } } } public static void main(String[] args) { new D().run(); } public void run() { long S = System.currentTimeMillis(); is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()); out = new FastWriter(System.out); solve(); out.flush(); long G = System.currentTimeMillis(); tr(G-S+"ms"); // Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){ // @Override // public void run() { // long s = System.currentTimeMillis(); // solve(); // out.flush(); // if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); // } // }; // t.start(); // t.join(); } private boolean eof() { if(lenbuf == -1)return true; int lptr = ptrbuf; while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false; try { is.mark(1000); while(true){ int b = is.read(); if(b == -1){ is.reset(); return true; }else if(!isSpaceChar(b)){ is.reset(); return false; } } } catch (IOException e) { return true; } } private final byte[] inbuf = new byte[1024]; public int lenbuf = 0, ptrbuf = 0; private int readByte() { if(lenbuf == -1)throw new InputMismatchException(); if(ptrbuf >= lenbuf){ ptrbuf = 0; try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } if(lenbuf <= 0)return -1; } return inbuf[ptrbuf++]; } private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } // private boolean isSpaceChar(int c) { return !(c >= 32 && c <= 126); } private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } private double nd() { return Double.parseDouble(ns()); } private char nc() { return (char)skip(); } private String ns() { int b = skip(); StringBuilder sb = new StringBuilder(); while(!(isSpaceChar(b))){ sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } private char[] ns(int n) { char[] buf = new char[n]; int b = skip(), p = 0; while(p < n && !(isSpaceChar(b))){ buf[p++] = (char)b; b = readByte(); } return n == p ? buf : Arrays.copyOf(buf, p); } private char[][] nm(int n, int m) { char[][] map = new char[n][]; for(int i = 0;i < n;i++)map[i] = ns(m); return map; } private int[] na(int n) { int[] a = new int[n]; for(int i = 0;i < n;i++)a[i] = ni(); return a; } private long[] nal(int n) { long[] a = new long[n]; for(int i = 0;i < n;i++)a[i] = nl(); return a; } private int ni() { int num = 0, b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private long nl() { long num = 0; int b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } public static class FastWriter { private static final int BUF_SIZE = 1<<13; private final byte[] buf = new byte[BUF_SIZE]; private final OutputStream out; private int ptr = 0; private FastWriter(){out = null;} public FastWriter(OutputStream os) { this.out = os; } public FastWriter(String path) { try { this.out = new FileOutputStream(path); } catch (FileNotFoundException e) { throw new RuntimeException("FastWriter"); } } public FastWriter write(byte b) { buf[ptr++] = b; if(ptr == BUF_SIZE)innerflush(); return this; } public FastWriter write(char c) { return write((byte)c); } public FastWriter write(char[] s) { for(char c : s){ buf[ptr++] = (byte)c; if(ptr == BUF_SIZE)innerflush(); } return this; } public FastWriter write(String s) { s.chars().forEach(c -> { buf[ptr++] = (byte)c; if(ptr == BUF_SIZE)innerflush(); }); return this; } private static int countDigits(int l) { if (l >= 1000000000) return 10; if (l >= 100000000) return 9; if (l >= 10000000) return 8; if (l >= 1000000) return 7; if (l >= 100000) return 6; if (l >= 10000) return 5; if (l >= 1000) return 4; if (l >= 100) return 3; if (l >= 10) return 2; return 1; } public FastWriter write(int x) { if(x == Integer.MIN_VALUE){ return write((long)x); } if(ptr + 12 >= BUF_SIZE)innerflush(); if(x < 0){ write((byte)'-'); x = -x; } int d = countDigits(x); for(int i = ptr + d - 1;i >= ptr;i--){ buf[i] = (byte)('0'+x%10); x /= 10; } ptr += d; return this; } private static int countDigits(long l) { if (l >= 1000000000000000000L) return 19; if (l >= 100000000000000000L) return 18; if (l >= 10000000000000000L) return 17; if (l >= 1000000000000000L) return 16; if (l >= 100000000000000L) return 15; if (l >= 10000000000000L) return 14; if (l >= 1000000000000L) return 13; if (l >= 100000000000L) return 12; if (l >= 10000000000L) return 11; if (l >= 1000000000L) return 10; if (l >= 100000000L) return 9; if (l >= 10000000L) return 8; if (l >= 1000000L) return 7; if (l >= 100000L) return 6; if (l >= 10000L) return 5; if (l >= 1000L) return 4; if (l >= 100L) return 3; if (l >= 10L) return 2; return 1; } public FastWriter write(long x) { if(x == Long.MIN_VALUE){ return write("" + x); } if(ptr + 21 >= BUF_SIZE)innerflush(); if(x < 0){ write((byte)'-'); x = -x; } int d = countDigits(x); for(int i = ptr + d - 1;i >= ptr;i--){ buf[i] = (byte)('0'+x%10); x /= 10; } ptr += d; return this; } public FastWriter write(double x, int precision) { if(x < 0){ write('-'); x = -x; } x += Math.pow(10, -precision)/2; // if(x < 0){ x = 0; } write((long)x).write("."); x -= (long)x; for(int i = 0;i < precision;i++){ x *= 10; write((char)('0'+(int)x)); x -= (int)x; } return this; } public FastWriter writeln(char c){ return write(c).writeln(); } public FastWriter writeln(int x){ return write(x).writeln(); } public FastWriter writeln(long x){ return write(x).writeln(); } public FastWriter writeln(double x, int precision){ return write(x, precision).writeln(); } public FastWriter write(int... xs) { boolean first = true; for(int x : xs) { if (!first) write(' '); first = false; write(x); } return this; } public FastWriter write(long... xs) { boolean first = true; for(long x : xs) { if (!first) write(' '); first = false; write(x); } return this; } public FastWriter write(IntUnaryOperator f, int... xs) { boolean first = true; for(int x : xs) { if (!first) write(' '); first = false; write(f.applyAsInt(x)); } return this; } public FastWriter write(LongUnaryOperator f, long... xs) { boolean first = true; for(long x : xs) { if (!first) write(' '); first = false; write(f.applyAsLong(x)); } return this; } public FastWriter writeln() { return write((byte)'\n'); } public FastWriter writeln(int... xs) { return write(xs).writeln(); } public FastWriter writeln(long... xs) { return write(xs).writeln(); } public FastWriter writeln(IntUnaryOperator f, int... xs) { return write(f, xs).writeln(); } public FastWriter writeln(LongUnaryOperator f, long... xs) { return write(f, xs).writeln(); } public FastWriter writeln(char[] line) { return write(line).writeln(); } public FastWriter writeln(char[]... map) { for(char[] line : map)write(line).writeln();return this; } public FastWriter writeln(String s) { return write(s).writeln(); } private void innerflush() { try { out.write(buf, 0, ptr); ptr = 0; } catch (IOException e) { throw new RuntimeException("innerflush"); } } public void flush() { innerflush(); try { out.flush(); } catch (IOException e) { throw new RuntimeException("flush"); } } public FastWriter print(byte b) { return write(b); } public FastWriter print(char c) { return write(c); } public FastWriter print(char[] s) { return write(s); } public FastWriter print(String s) { return write(s); } public FastWriter print(int x) { return write(x); } public FastWriter print(long x) { return write(x); } public FastWriter print(double x, int precision) { return write(x, precision); } public FastWriter println(char c){ return writeln(c); } public FastWriter println(int x){ return writeln(x); } public FastWriter println(long x){ return writeln(x); } public FastWriter println(double x, int precision){ return writeln(x, precision); } public FastWriter print(int... xs) { return write(xs); } public FastWriter print(long... xs) { return write(xs); } public FastWriter print(IntUnaryOperator f, int... xs) { return write(f, xs); } public FastWriter print(LongUnaryOperator f, long... xs) { return write(f, xs); } public FastWriter println(int... xs) { return writeln(xs); } public FastWriter println(long... xs) { return writeln(xs); } public FastWriter println(IntUnaryOperator f, int... xs) { return writeln(f, xs); } public FastWriter println(LongUnaryOperator f, long... xs) { return writeln(f, xs); } public FastWriter println(char[] line) { return writeln(line); } public FastWriter println(char[]... map) { return writeln(map); } public FastWriter println(String s) { return writeln(s); } public FastWriter println() { return writeln(); } } public static void trnz(int... o) { for(int i = 0;i < o.length;i++)if(o[i] != 0)System.out.print(i+":"+o[i]+" "); System.out.println(); } // print ids which are 1 public static void trt(long... o) { Queue stands = new ArrayDeque<>(); for(int i = 0;i < o.length;i++){ for(long x = o[i];x != 0;x &= x-1)stands.add(i<<6|Long.numberOfTrailingZeros(x)); } System.out.println(stands); } public static void tf(boolean... r) { for(boolean x : r)System.out.print(x?'#':'.'); System.out.println(); } public static void tf(boolean[]... b) { for(boolean[] r : b) { for(boolean x : r)System.out.print(x?'#':'.'); System.out.println(); } System.out.println(); } public void tf(long[]... b) { if(INPUT.length() != 0) { for (long[] r : b) { for (long x : r) { for (int i = 0; i < 64; i++) { System.out.print(x << ~i < 0 ? '#' : '.'); } } System.out.println(); } System.out.println(); } } public void tf(long... b) { if(INPUT.length() != 0) { for (long x : b) { for (int i = 0; i < 64; i++) { System.out.print(x << ~i < 0 ? '#' : '.'); } } System.out.println(); } } private void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); } }