ll@n,@m,@a[m],d[n],p=0;
rep(i,n)d[i]=i;
rrep[a](x,m){
	swap(d[x-1],d[x]);
	p+=(p==x-1)-(p==x);
	rrep(i,p){
		d[i]<?=d[i+1]+1;
	}
	rep(i,p+1,n){
		d[i]<?=d[i-1]+1;
	}
}
wt(((d+1))(n-1));