// dfmt off
T lread(T=long)(){return readln.chomp.to!T;}T[] lreads(T=long)(long n){return iota(n).map!((_)=>lread!T).array;}
T[] aryread(T=long)(){return readln.split.to!(T[]);}void arywrite(T)(T a){a.map!text.join(' ').writeln;}
void scan(L...)(ref L A){auto l=readln.split;foreach(i,T;L){A[i]=l[i].to!T;}}alias sread=()=>readln.chomp();
void dprint(L...)(lazy L A){debug{auto l=new string[](L.length);static foreach(i,a;A)l[i]=a.text;arywrite(l);}}
static immutable MOD=10^^9+7;alias PQueue(T,alias l="b<a")=BinaryHeap!(Array!T,l);import std, core.bitop;
// dfmt on

void main()
{
    long N = lread();
    auto A = lreads(N);
    auto B = new long[][](2);
    foreach (i; 0 .. N)
    {
        B[i & 1] ~= A[i];
    }
    B[0].sort();
    B[1].sort();
    long[2] idx;
    foreach (i; 0 .. N)
    {
        A[i] = B[i & 1][idx[i & 1]++];
    }
    long[long] d;
    auto C = A.dup;
    C.sort();
    foreach (i; 0 .. N)
        d[C[i]] = i;
    long ans;
    foreach (i; 0 .. N)
    {
        ans += max(0, i - d[A[i]]);
    }
    dprint(A);
    writeln(ans);
}
