import types _atcoder_code = """ # Python port of AtCoder Library. __all__ = ["string","lazysegtree","convolution","maxflow","modint" ,"mincostflow","segtree","_scc","_math","math","dsu","twosat","fenwicktree","scc","_bit","lca","unverified","graph","matrix","algebra","combinatorics"] __version__ = '0.0.1' """ atcoder = types.ModuleType('atcoder') exec(_atcoder_code, atcoder.__dict__) _atcoder__bit_code = """ def _ceil_pow2(n: int) -> int: x = 0 while (1 << x) < n: x += 1 return x def _bsf(n: int) -> int: x = 0 while n % 2 == 0: x += 1 n //= 2 return x """ atcoder._bit = types.ModuleType('atcoder._bit') exec(_atcoder__bit_code, atcoder._bit.__dict__) _atcoder_segtree_code = """ import typing # import atcoder._bit class SegTree: ''' Segment Tree Library. op(S,S) -> S e = Identity element SegTree(op,e,n) := Initialized by [e]*(n) SegTree(op,e,vector) := Initialized by vector ''' def __init__(self, op: typing.Callable[[typing.Any, typing.Any], typing.Any], e: typing.Any, v: typing.Union[int, typing.List[typing.Any]]) -> None: self._op = op self._e = e if isinstance(v, int): v = [e] * v self._n = len(v) self._log = atcoder._bit._ceil_pow2(self._n) self._size = 1 << self._log self._d = [e] * (2 * self._size) for i in range(self._n): self._d[self._size + i] = v[i] for i in range(self._size - 1, 0, -1): self._update(i) def set(self, p: int, x: typing.Any) -> None: ''' a[p] -> x in O(logN). ''' assert 0 <= p < self._n p += self._size self._d[p] = x for i in range(1, self._log + 1): self._update(p >> i) def increment(self, p: int, x : typing.Any) -> None: ''' a[p] -> a[p] + x in O(logN). ''' assert 0 <= p < self._n p += self._size self._d[p] += x for i in range(1,self._log + 1): self._update(p >> i) def get(self, p: int) -> typing.Any: ''' return a[p] in O(1). ''' assert 0 <= p < self._n return self._d[p + self._size] def prod(self, left: int, right: int) -> typing.Any: ''' return op(a[l...r)) in O(logN). ''' assert 0 <= left <= right <= self._n sml = self._e smr = self._e left += self._size right += self._size while left < right: if left & 1: sml = self._op(sml, self._d[left]) left += 1 if right & 1: right -= 1 smr = self._op(self._d[right], smr) left >>= 1 right >>= 1 return self._op(sml, smr) def all_prod(self) -> typing.Any: return self._d[1] def max_right(self, left: int, f: typing.Callable[[typing.Any], bool]) -> int: ''' let f(S) -> bool and l is const. return maximum r for which f(op[l...r)) == true is satisfied, in O(logN). ''' assert 0 <= left <= self._n # assert f(self._e) if left == self._n: return self._n left += self._size sm = self._e first = True while first or (left & -left) != left: first = False while left % 2 == 0: left >>= 1 if not f(self._op(sm, self._d[left])): while left < self._size: left *= 2 if f(self._op(sm, self._d[left])): sm = self._op(sm, self._d[left]) left += 1 return left - self._size sm = self._op(sm, self._d[left]) left += 1 return self._n def min_left(self, right: int, f: typing.Callable[[typing.Any], bool]) -> int: ''' let f(S) -> bool and r is const. return minimum l for which f(op[l...r)) == true is satisfied, in O(logN). ''' assert 0 <= right <= self._n # assert f(self._e) if right == 0: return 0 right += self._size sm = self._e first = True while first or (right & -right) != right: first = False right -= 1 while right > 1 and right % 2: right >>= 1 if not f(self._op(self._d[right], sm)): while right < self._size: right = 2 * right + 1 if f(self._op(self._d[right], sm)): sm = self._op(self._d[right], sm) right -= 1 return right + 1 - self._size sm = self._op(self._d[right], sm) return 0 def _update(self, k: int) -> None: self._d[k] = self._op(self._d[2 * k], self._d[2 * k + 1]) """ atcoder.segtree = types.ModuleType('atcoder.segtree') atcoder.segtree.__dict__['atcoder'] = atcoder atcoder.segtree.__dict__['atcoder._bit'] = atcoder._bit exec(_atcoder_segtree_code, atcoder.segtree.__dict__) SegTree = atcoder.segtree.SegTree ''' Python3(PyPy3) Template for Programming-Contest. author : sgsw generated : 2021/08/14 when : 23:49:30 ''' import sys def input(): return sys.stdin.readline().rstrip() DXY = [(0, -1), (1, 0), (0, 1), (-1, 0)] # LDRU mod = 998244353 inf = 1 << 64 # from atcoder.segtree import SegTree def main(): n = int(input()) a = list(map(int,input().split())) seg = SegTree(lambda x,y : max(x,y),-10**18,a) if sorted(a) == a: print(0) else: #case 1 cnt = 0 is_sorted = [True]*(n) for i in reversed(range(0,n)): if i == n - 1: is_sorted[i] = True else: is_sorted[i - 1] = is_sorted[i] & (a[i - 1] <= a[i]) for l in range(2,n): cnt += not (a[l - 2] <= a[l - 1]) lval = seg.prod(0,l) if lval <= a[l] and cnt == 1 and is_sorted[l]: print(1) return print(2) return 0 if __name__ == "__main__": main()