Calculate students marks grade using Java

import java.io.*;


class ssvstud 
{ 
public static void main(String arg[]) 
{ 
int s[]=new int[9]; 
int n,z=0,x=0,y=0,w=0; 
s[0]=60;s[1]=70;s[2]=80;s[3]=72;s[4]=48;s[5]=55;s[6]=25;s[7]=90;s[8]=99; 
n=9; 
for(int i=0;i<n;i++) 
{ 
if(s[i]>=81 && s[i]<=100) 
z=z+1; 
} 
System.out.println("students in the range(81-100)is="+z); 
for(int i=0;i<n;i++) 
{ 
if(s[i]>=61 && s[i]<=80) 
y=y+1; 
} 
System.out.println("students in the range(61-80)is="+y); 
for(int i=0;i<n;i++) 
{ 
if(s[i]>=41 && s[i]<=60) 
x=x+1; 
} 
System.out.println("students in the range(41-60)is="+x); 
for(int i=0;i<n;i++) 
{ 
if(s[i]>=0 && s[i]<=40) 
w=w+1; 
} 
System.out.println("students in the range(0-40)is="+w); 
} 
}