private int [] combinar(int []left, int right[], int[] lista){
		int nleft=left.length;
		int nright=right.length;
		int l=0,r=0,li=0;
		while(l<nleft && r<nright){
			if(left[l]<=right[r]){
				lista[li]=left[l];
				l++;
			}
			else{
				lista[li]=right[r];
				r++;
			}
			li++;
		}
		while(l<nleft){
			lista[li]=left[l];
			l++;
			li++;
		}
		while(r<nright){
			lista[li]=right[r];
			r++;
			li++;
		}
		return lista;
	}