Saddle Point in java

import java.io.*;

class sad
{

int a[][],i,j,k,max,min,sa=0,f=0;

void input()throws Exception
{
a=new int[5][5];


DataInputStream dd= new DataInputStream(System.in);

System.out.println("Enter elements in an array");

for(i=0;i<4;i++)
for(j=0;j<4;j++)
a[i][j]=Integer.parseInt(dd.readLine());


}

void maxmin()
{

for(i=0;i<4;i++)
{
max=a[0][i];
min=a[i][0];

for(k=0;k<4;k++)
if(a[i][k]<min)
min= a[i][k];

for(k=0;k<4;k++)
if(a[k][i]>max)
max= a[k][i];

a[i][4]=min;
a[4][i]=max;

}


for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
System.out.print(a[i][j]);
System.out.println();

}

}

void sadd()
{

for(i=0;i<4;i++)
{
for(j=0;j<4;j++)

if((a[i][j]==a[i][4])&&(a[i][j]==a[4][j]))
{
f=1;
System.out.println("Saddle point found at "+i+" "+j);
}
}

if(f==0)
System.out.println("Saddle point not found");

}




}
class saddle
{
public static void main(String args[])throws Exception
{
sad ob=new sad();
ob.input();
ob.maxmin();
ob.sadd();


}
}