import core.bitop, std.bitmanip;
import core.checkedint;
import std.algorithm, std.functional;
import std.array, std.container;
import std.bigint;
import std.conv;
import std.math, std.numeric;
import std.range, std.range.interfaces;
import std.stdio, std.string;
import std.typecons;

void main()
{
    int n;
    readf("%s", &n);
    readln;
    
    auto arr = readln.chomp.split.map!(to!int).array;
    
    if (arr.isSorted()) {
        writeln("YES");
        return;
    }
    
    foreach (i; 0 .. n) {
        foreach (j; i+1 .. n) {
            swap(arr[i], arr[j]);
            if (arr.isSorted()) {
                writeln("YES");
                return;
            }
            
            swap(arr[i], arr[j]);
        }
    }
    
    writeln("NO");
}