for ( i = 2 ; i < n-2 ; i++) {
       k1[i] = (- p*h[i]*(h[i+1]-h[i-1])/2
                   +  nu * (h[i+1]-2*h[i]+h[i-1])
                   - a*(h[i+2]-2*h[i+1]+ 2*h[i-1]-h[i-2])/2)*dt;
        }
		for ( i = 4 ; i < n-4 ; i++) {
       k2[i] = (- p*(h[i]+ 0.5*k1[i])*(h[i+1] + 0.5*k1[i+1] -h[i-1] - 0.5*k1[i-1])/2
                   +  nu * (h[i+1]+ 0.5*k1[i+1] -2*(h[i] + 0.5*k1[i]) + h[i-1] + 0.5*k1[i-1])
                   - a*(h[i+2] + 0.5*k1[i+2] -2*(h[i+1] + 0.5*k1[i+1])+ 2*(h[i-1] + 0.5*k1[i-1])-(h[i-2] + 0.5*k1[i-2]))/2)*dt;
        }
		
		for ( i = 6 ; i < n-6 ; i++) {
       k3[i] = (- p*(h[i]+ 0.5*k2[i])*(h[i+1] + 0.5*k2[i+1] -h[i-1] - 0.5*k2[i-1])/2
                   +  nu * (h[i+1]+ 0.5*k2[i+1] -2*(h[i] + 0.5*k2[i]) + h[i-1] + 0.5*k2[i-1])
                   - a*(h[i+2] + 0.5*k2[i+2] -2*(h[i+1] + 0.5*k2[i+1])+ 2*(h[i-1] + 0.5*k2[i-1])-(h[i-2] + 0.5*k2[i-2]))/2)*dt;
        }
		
		for ( i = 8 ; i < n-8 ; i++) {
       k4[i] = (- p*(h[i]+ k3[i])*(h[i+1] + k3[i+1] -h[i-1] - k3[i-1])/2
                   +  nu * (h[i+1]+ k3[i+1] -2*(h[i] + k3[i]) + h[i-1] + k3[i-1])
                   - a*(h[i+2] + k3[i+2] -2*(h[i+1] + k3[i+1])+ 2*(h[i-1] + k3[i-1])-(h[i-2] + k3[i-2]))/2)*dt;
        }
		
		
 for ( i = 8 ; i < n - 8 ; i++) {
       ho[i] = h[i] + (1/6)*(k1[i] + 2*k2[i] + 2*k3[i] + k4[i]); 
	   }
 for ( i = 8 ; i < n -8 ; i++) {
       h[i] = ho[i] ;
	   }