import macros;macro ImportExpand(s:untyped):untyped = parseStmt($s[2])
# verification-helper: PROBLEM https://judge.yosupo.jp/problem/point_add_range_sum
{.checks: off.}
ImportExpand "cplib/tmpl/citrus.nim" <=== "when not declared CPLIB_TMPL_CITRUS:\n    const CPLIB_TMPL_CITRUS* = 1\n    {.warning[UnusedImport]: off.}\n    {.hint[XDeclaredButNotUsed]: off.}\n    import os\n    import algorithm\n    import sequtils\n    import tables\n    import macros\n    import std/math\n    import sets\n    import strutils\n    import strformat\n    import sugar\n    import streams\n    import deques\n    import bitops\n    import heapqueue\n    import options\n    import hashes\n    const MODINT998244353* = 998244353\n    const MODINT1000000007* = 1000000007\n    #[ include cplib/utils/constants ]#\n    when not declared CPLIB_UTILS_CONSTANTS:\n        const CPLIB_UTILS_CONSTANTS* = 1\n        const INF32*: int32 = 100100111.int32\n        const INF64*: int = int(3300300300300300491)\n    const INFL = INF64\n    type double* = float64\n    let readNext = iterator(getsChar: bool = false): string {.closure.} =\n        while true:\n            var si: string\n            try: si = stdin.readLine\n            except EOFError: yield \"\"\n            for s in si.split:\n                if getsChar:\n                    for i in 0..<s.len():\n                        yield s[i..i]\n                else:\n                    if s.isEmptyOrWhitespace: continue\n                    yield s\n    proc input*(t: typedesc[string]): string = readNext()\n    proc input*(t: typedesc[char]): char = readNext(true)[0]\n    proc input*(t: typedesc[int]): int = readNext().parseInt\n    proc input*(t: typedesc[float]): float = readNext().parseFloat\n    macro input*(t: typedesc, n: varargs[int]): untyped =\n        var repStr = \"\"\n        for arg in n:\n            repStr &= &\"({arg.repr}).newSeqWith \"\n        parseExpr(&\"{repStr}input({t})\")\n    macro input*(ts: varargs[auto]): untyped =\n        var tupStr = \"\"\n        for t in ts:\n            tupStr &= &\"input({t.repr}),\"\n        parseExpr(&\"({tupStr})\")\n    macro input*(n: int, ts: varargs[auto]): untyped =\n        for typ in ts:\n            if typ.typeKind != ntyAnything:\n                error(\"Expected typedesc, got \" & typ.repr, typ)\n        parseExpr(&\"({n.repr}).newSeqWith input({ts.repr})\")\n    proc `fmtprint`*(x: int or string or char or bool): string = return $x\n    proc `fmtprint`*(x: float or float32 or float64): string = return &\"{x:.16f}\"\n    proc `fmtprint`*[T](x: seq[T] or Deque[T] or HashSet[T] or set[T]): string = return x.toSeq.join(\" \")\n    proc `fmtprint`*[T, N](x: array[T, N]): string = return x.toSeq.join(\" \")\n    proc `fmtprint`*[T](x: HeapQueue[T]): string =\n        var q = x\n        while q.len != 0:\n            result &= &\"{q.pop()}\"\n            if q.len != 0: result &= \" \"\n    proc `fmtprint`*[T](x: CountTable[T]): string =\n        result = x.pairs.toSeq.mapIt(&\"{it[0]}: {it[1]}\").join(\" \")\n    proc `fmtprint`*[K, V](x: Table[K, V]): string =\n        result = x.pairs.toSeq.mapIt(&\"{it[0]}: {it[1]}\").join(\" \")\n    proc print*(prop: tuple[f: File, sepc: string, endc: string, flush: bool], args: varargs[string, `fmtprint`]) =\n        for i in 0..<len(args):\n            prop.f.write(&\"{args[i]}\")\n            if i != len(args) - 1: prop.f.write(prop.sepc) else: prop.f.write(prop.endc)\n        if prop.flush: prop.f.flushFile()\n    proc print*(args: varargs[string, `fmtprint`]) = print((f: stdout, sepc: \" \", endc: \"\\n\", flush: false), args)\n    const LOCAL_DEBUG{.booldefine.} = false\n    macro getSymbolName(x: typed): string = x.toStrLit\n    macro debug*(args: varargs[untyped]): untyped =\n        when LOCAL_DEBUG:\n            result = newNimNode(nnkStmtList, args)\n            template prop(e: string = \"\"): untyped = (f: stderr, sepc: \"\", endc: e, flush: true)\n            for i, arg in args:\n                if arg.kind == nnkStrLit:\n                    result.add(quote do: print(prop(), \"\\\"\", `arg`, \"\\\"\"))\n                else:\n                    result.add(quote do: print(prop(\": \"), getSymbolName(`arg`)))\n                    result.add(quote do: print(prop(), `arg`))\n                if i != args.len - 1: result.add(quote do: print(prop(), \", \"))\n                else: result.add(quote do: print(prop(), \"\\n\"))\n        else:\n            return (quote do: discard)\n    proc `%`*(x: SomeInteger, y: SomeInteger): int =\n        result = x mod y\n        if y > 0 and result < 0: result += y\n        if y < 0 and result > 0: result += y\n    proc `//`*(x: SomeInteger, y: SomeInteger): int =\n        result = x div y\n        if y > 0 and result * y > x: result -= 1\n        if y < 0 and result * y < x: result -= 1\n    proc `^`*(x: SomeInteger, y: SomeInteger): int = x xor y\n    proc `&`*(x: SomeInteger, y: SomeInteger): int = x and y\n    proc `|`*(x: SomeInteger, y: SomeInteger): int = x or y\n    proc `>>`*(x: SomeInteger, y: SomeInteger): int = x shr y\n    proc `<<`*(x: SomeInteger, y: SomeInteger): int = x shl y\n    proc `%=`*(x: var SomeInteger, y: SomeInteger): void = x = x % y\n    proc `//=`*(x: var SomeInteger, y: SomeInteger): void = x = x // y\n    proc `^=`*(x: var SomeInteger, y: SomeInteger): void = x = x ^ y\n    proc `&=`*(x: var SomeInteger, y: SomeInteger): void = x = x & y\n    proc `|=`*(x: var SomeInteger, y: SomeInteger): void = x = x | y\n    proc `>>=`*(x: var SomeInteger, y: SomeInteger): void = x = x >> y\n    proc `<<=`*(x: var SomeInteger, y: SomeInteger): void = x = x << y\n    proc `[]`*(x, n: int): bool = (x and (1 shl n)) != 0\n    proc `[]=`*(x: var int, n: int, i: bool) =\n        if i: x = x or (1 << n)\n        else: (if x[n]: x = x xor (1 << n))\n    proc pow*(a, n: int, m = INF64): int =\n        var\n            rev = 1\n            a = a\n            n = n\n        while n > 0:\n            if n % 2 != 0: rev = (rev * a) mod m\n            if n > 1: a = (a * a) mod m\n            n >>= 1\n        return rev\n    #[ include cplib/math/isqrt ]#\n    when not declared CPLIB_MATH_ISQRT:\n        const CPLIB_MATH_ISQRT* = 1\n        proc isqrt*(n: int): int =\n            var x = n\n            var y = (x + 1) shr 1\n            while y < x:\n                x = y\n                y = (x + n div x) shr 1\n            return x\n    proc chmax*[T](x: var T, y: T): bool {.discardable.} = (if x < y: (x = y; return true; ) return false)\n    proc chmin*[T](x: var T, y: T): bool {.discardable.} = (if x > y: (x = y; return true; ) return false)\n    proc `max=`*[T](x: var T, y: T) = x = max(x, y)\n    proc `min=`*[T](x: var T, y: T) = x = min(x, y)\n    proc at*(x: char, a = '0'): int = int(x) - int(a)\n    proc Yes*(b: bool = true): void = print(if b: \"Yes\" else: \"No\")\n    proc No*(b: bool = true): void = Yes(not b)\n    proc YES_upper*(b: bool = true): void = print(if b: \"YES\" else: \"NO\")\n    proc NO_upper*(b: bool = true): void = Yes_upper(not b)\n    const DXY* = [(0, -1), (0, 1), (-1, 0), (1, 0)]\n    const DDXY* = [(1, -1), (1, 0), (1, 1), (0, -1), (0, 1), (-1, -1), (-1, 0), (-1, 1)]\n    macro exit*(statement: untyped): untyped = (quote do: (`statement`; quit()))\n    proc initHashSet[T](): Hashset[T] = initHashSet[T](0)\n"
ImportExpand "cplib/collections/avlset.nim" <=== "when not declared CPLIB_COLLECTIONS_AVLSET:\n    const CPLIB_COLLECTIONS_AVLSET* = 1\n    #[ import cplib/collections/avltreenode ]#\n    when not declared CPLIB_COLLECTIONS_AVLTREE:\n        const CPLIB_COLLECTIONS_AVLTREE* = 1\n        # 以下をNimに移植\n        # https://nachiavivias.github.io/cp-library/cpp/array/bbst-list.html\n        type AvlTreeNode*[K] = ref object\n            l*, r*, p*: AvlTreeNode[K]\n            h*, len*: int\n            key*: K\n        proc get_avltree_nilnode*[K](): AvlTreeNode[K] =\n            let nil_node {.global.} = (block:\n                var nil_node = AvlTreeNode[K](h: 0, len: 0)\n                nil_node.l = nil_node\n                nil_node.r = nil_node\n                nil_node.p = nil_node\n                nil_node\n            )\n            return nil_node\n        proc update[K](node: AvlTreeNode[K]) =\n            node.h = max(node.l.h + 1, node.r.h + 1)\n            node.len = 1 + node.l.len + node.r.len\n        proc set_children[K](node, l, r: AvlTreeNode[K]) =\n            node.l = l\n            if l != get_avltree_nilnode[K](): l.p = node\n            node.r = r\n            if r != get_avltree_nilnode[K](): r.p = node\n            node.update()\n        proc rebalance[K](node: AvlTreeNode[K]): AvlTreeNode[K] =\n            var node = node\n            var l = node.l\n            var r = node.r\n            if l.h + 1 < r.h:\n                var rl = r.l\n                var rr = r.r\n                if rl.h <= rr.h:\n                    r.p = node.p\n                    node.set_children(l, rl)\n                    r.set_children(node, rr)\n                    return r\n                else:\n                    rl.p = node.p\n                    node.set_children(l, rl.l)\n                    r.set_children(rl.r, rr)\n                    rl.set_children(node, r)\n                    return rl\n            elif r.h + 1 < l.h:\n                var ll = l.l\n                var lr = l.r\n                if lr.h <= ll.h:\n                    l.p = node.p\n                    node.set_children(lr, r)\n                    l.set_children(ll, node)\n                    return l\n                else:\n                    lr.p = node.p\n                    node.set_children(lr.r, r)\n                    l.set_children(ll, lr.l)\n                    lr.set_children(l, node)\n                    return lr\n            node.update\n            return node\n        proc rebalance_to_root[K](node: AvlTreeNode[K]): AvlTreeNode[K] =\n            var node = node\n            while node.p != get_avltree_nilnode[K]():\n                var cp = node.p\n                if cp.l == node: cp.l = node.rebalance\n                else: cp.r = node.rebalance\n                node = cp\n            return node.rebalance\n        proc rootOf*[K](node: AvlTreeNode[K]): AvlTreeNode[K] =\n            result = node\n            while result.p != get_avltree_nilnode[K](): result = result.p\n        proc node_search[K](node: AvlTreeNode[K], key: K, strict: bool): (AvlTreeNode[K], AvlTreeNode[K]) =\n            var node = node\n            var result_l = get_avltree_nilnode[K]()\n            var result_r = get_avltree_nilnode[K]()\n            while node != get_avltree_nilnode[K]():\n                if (strict and key < node.key) or (not strict and key <= node.key):\n                    result_r = node\n                    node = node.l\n                else:\n                    result_l = node\n                    node = node.r\n            return (result_l, result_r)\n        proc lower_bound_node*[K](node: AvlTreeNode[K], key: K): (AvlTreeNode[K], AvlTreeNode[K]) = node_search[K](node, key, false)\n        proc upper_bound_node*[K](node: AvlTreeNode[K], key: K): (AvlTreeNode[K], AvlTreeNode[K]) = node_search[K](node, key, true)\n        proc insert*[K](node, x: AvlTreeNode[K]): AvlTreeNode[K] =\n            if node == get_avltree_nilnode[K](): return x\n            var (ql, qr) = node.lower_bound_node(x.key)\n            if ql != get_avltree_nilnode[K]() and ql.r == get_avltree_nilnode[K]():\n                ql.set_children(ql.l, x)\n                return ql.rebalance_to_root\n            qr.set_children(x, qr.r)\n            return qr.rebalance_to_root\n        proc erase*[K](node, x, nxt: AvlTreeNode[K]): AvlTreeNode[K] =\n            var xp = x.p\n            result = get_avltree_nilnode[K]()\n            if x.r == get_avltree_nilnode[K]():\n                var xl = x.l\n                if xl != get_avltree_nilnode[K](): xl.p = xp\n                if xp != get_avltree_nilnode[K]():\n                    if xp.l == x: xp.l = xl\n                    else: xp.r = xl\n                if xp == get_avltree_nilnode[K](): result = xl\n                else: result = xp.rebalance_to_root\n            else:\n                var nxtp = nxt.p\n                var nxtr = nxt.r\n                if xp != get_avltree_nilnode[K]():\n                    if xp.l == x: xp.l = nxt\n                    else: xp.r = nxt\n                nxt.p = xp\n                nxt.l = x.l\n                if nxt.l != get_avltree_nilnode[K](): nxt.l.p = nxt\n                if x.r == nxt:\n                    nxt.update\n                    result = nxt.rebalance_to_root\n                else:\n                    if nxtp.l == nxt: nxtp.l = nxtr\n                    else: nxtp.r = nxtr\n                    if nxtr != get_avltree_nilnode[K](): nxtr.p = nxtp\n                    nxt.r = x.r\n                    nxt.r.p = nxt\n                    nxt.update\n                    result = nxtp.rebalance_to_root\n            x.l = get_avltree_nilnode[K]()\n            x.r = get_avltree_nilnode[K]()\n            x.p = get_avltree_nilnode[K]()\n            x.update\n        proc next*[K](node: AvlTreeNode[K]): AvlTreeNode[K] =\n            var node = node\n            if node.r != get_avltree_nilnode[K]():\n                node = node.r\n                while node.l != get_avltree_nilnode[K](): node = node.l\n                return node\n            while node.p.r == node: node = node.p\n            return node.p\n        proc prev*[K](node: AvlTreeNode[K]): AvlTreeNode[K] =\n            var node = node\n            if node.l != get_avltree_nilnode[K]():\n                node = node.l\n                while node.r != get_avltree_nilnode[K](): node = node.r\n                return node\n            while node.p.l == node: node = node.p\n            return node.p\n        proc get*[K](node: AvlTreeNode[K], idx: int): AvlTreeNode[K] =\n            assert idx >= 0\n            if idx >= node.len: return get_avltree_nilnode[K]()\n            result = node\n            var idx = idx\n            while result.l.len != idx:\n                if result.l.len < idx:\n                    idx -= result.l.len + 1\n                    result = result.r\n                else:\n                    result = result.l\n        proc index*[K](node: AvlTreeNode[K]): int =\n            var node = node\n            if node == get_avltree_nilnode[K](): return 0\n            result = node.l.len\n            while node.p != get_avltree_nilnode[K]():\n                if node.p.r == node: result += node.p.l.len + 1\n                node = node.p\n    \n    import options\n    import sequtils\n    import strutils\n\n    type AvlSortedMultiSet*[T] = object\n        root*: AvlTreeNode[T]\n\n    proc len*[T](self: AvlSortedMultiSet[T]): int = self.root.len\n    proc lowerBound*[T](self: AvlSortedMultiSet[T], x: T): int =\n        var (ql, qr) = self.root.lower_bound_node(x)\n        if qr == get_avltree_nilnode[T](): return self.len\n        return qr.index\n    proc index*[T](self: AvlSortedMultiSet[T], x: T): int = self.lowerBound(x)\n    proc upperBound*[T](self: AvlSortedMultiSet[T], x: T): int =\n        var (ql, qr) = self.root.upper_bound_node(x)\n        if qr == get_avltree_nilnode[T](): return self.len\n        return qr.index\n    proc index_right*[T](self: AvlSortedMultiSet[T], x: T): int = self.upperBound(x)\n    proc count*[T](self: AvlSortedMultiSet[T], x: T): int = self.upperBound(x) - self.lowerBound(x)\n    proc newnode[T](x: T): AvlTreeNode[T] =\n        var nil_node = get_avltree_nilnode[T]()\n        return AvlTreeNode[T](p: nil_node, l: nil_node, r: nil_node, len: 1, h: 1, key: x)\n    proc lt*[T](self: AvlSortedMultiSet[T], x: T): Option[T] =\n        var (node, _) = self.root.lower_bound_node(x)\n        if node == get_avltree_nilnode[T](): return none(T)\n        return some(node.key)\n    proc le*[T](self: AvlSortedMultiSet[T], x: T): Option[T] =\n        var (node, _) = self.root.upper_bound_node(x)\n        if node == get_avltree_nilnode[T](): return none(T)\n        return some(node.key)\n    proc gt*[T](self: AvlSortedMultiSet[T], x: T): Option[T] =\n        var (_, node) = self.root.upper_bound_node(x)\n        if node == get_avltree_nilnode[T](): return none(T)\n        return some(node.key)\n    proc ge*[T](self: AvlSortedMultiSet[T], x: T): Option[T] =\n        var (_, node) = self.root.lower_bound_node(x)\n        if node == get_avltree_nilnode[T](): return none(T)\n        return some(node.key)\n    proc contains*[T](self: AvlSortedMultiSet[T], x: T): bool =\n        var (_, node) = self.root.lower_bound_node(x)\n        return node != get_avltree_nilnode[T]() and node.key == x\n    proc incl*[T](self: var AvlSortedMultiSet[T], x: T) =\n        var node = newnode(x)\n        self.root = self.root.insert(node)\n    proc excl*[T](self: var AvlSortedMultiSet[T], x: T): bool {.discardable.} =\n        if x notin self: return false\n        var (_, node) = self.root.lower_bound_node(x)\n        self.root = self.root.erase(node, node.next)\n        return true\n    proc `[]`*[T](self: AvlSortedMultiSet[T], idx: int): T =\n        assert idx < self.root.len\n        return self.root.get(idx).key\n    proc `[]`*[T](self: AvlSortedMultiSet[T], idx: BackwardsIndex): T =\n        var idx = self.len - int(idx)\n        return self[idx]\n    proc pop*[T](self: var AvlSortedMultiSet[T], idx: int = -1): T =\n        var idx = idx\n        if idx < 0: idx = self.len + idx\n        assert idx < self.root.len\n        var node = self.root.get(idx)\n        result = node.key\n        self.root = self.root.erase(node, node.next)\n    iterator items*[T](self: AvlSortedMultiSet[T]): T =\n        var stack = @[(0, self.root)]\n        while stack.len > 0:\n            var (t, node) = stack.pop\n            if t == 0:\n                stack.add((1, node))\n                if node.l != get_avltree_nilnode[T](): stack.add((0, node.l))\n            elif t == 1:\n                yield node.key\n                if node.r != get_avltree_nilnode[T](): stack.add((0, node.r))\n    proc `$`*[T](self: AvlSortedMultiSet[T]): string = self.toSeq.join(\" \")\n    proc initAvlSortedMultiSet*[T](v: seq[T] = @[]): AvlSortedMultiSet[T] =\n        result = AvlSortedMultiSet[T](root: get_avltree_nilnode[T]())\n        for item in v: result.incl(item)\n"

var n = input(int)
var lr = newSeqWith(n, input(int, int)).sortedByIt(it[1])

var st = initAvlSortedMultiSet[int]()
for i in 0..<n:
    var (l, r) = lr[i]
    var p = st.index(l+1)
    if p == 0:
        st.incl(r)
    else:
        discard st.pop(p-1)
        st.incl(r)
print(st.len - 1)