#include <iostream>
#include <fstream>

using namespace std;

int main()
{
int n,a[100000],i,ok,aux,nr=0;
fstream f,g;
f.open("inv.in",ios::in);
g.open("inv.out",ios::out);
f>>n;
for(i=1;i<=n;i++)
    f>>a[i];
do{
    ok=0;
    for(i=1;i<n;i++)
        if(a[i]>a[i+1])
    {
        aux=a[i];
        a[i]=a[i+1];
        a[i+1]=aux;
        ok=1;
        nr++;

    }
}while(ok==1);
g<<nr<<endl;
}