x[1010],s,i,j;
main(k){
	for(scanf("%*d%d",&k);~scanf("%d",x+i);i++);
	for(;--i>0;x[i]<x[i-1]?i=0:0)for(j=k;x[j];j++)x[j-k]>x[j]?x[j-k]^=x[j]^=x[j-k]^=x[j],s++:0;
	s=!printf("%d",i|s);
}