Martix Multiplication

import java.io.*;
class matmul
{
public static void main(String args[])throws IOException
{
int a[][]=new int[5][5];
int b[][]=new int[5][5];
int c[][]=new int[5][5];
int i,j,r1,r2,c1,c2,k;
DataInputStream in=new DataInputStream(System.in);
System.out.println("Enter row & column of Matrix A:");
r1=Integer.parseInt(in.readLine());
c1=Integer.parseInt(in.readLine());
System.out.println("Enter row & column of Matrix B:");
r2=Integer.parseInt(in.readLine());
c2=Integer.parseInt(in.readLine());
if(c1==r2)
{
System.out.println("enter the elements for matrix a");
for(i=0;i<r1;i++)
{
for(j=0;j<c1;j++)
{
a[i][j]=Integer.parseInt(in.readLine());
}
}
System.out.println("enter the elements for matrix b");
for(i=0;i<r2;i++)
{
for(j=0;j<c2;j++)
{
b[i][j]=Integer.parseInt(in.readLine());
}
}
for(i=0;i<r1;i++)
{
for(j=0;j<c2;j++)
{
c[i][j]=0;
for(k=0;k<c1;k++)
{
c[i][j]=c[i][j]+a[i][k]*b[k][j];
}
}
}
System.out.println("matrix a is");
for(i=0;i<r1;i++)
{
for(j=0;j<c1;j++)
{
System.out.print(a[i][j]+"\t");
}
System.out.println("");
}
System.out.println("matrix b is");
for(i=0;i<r2;i++)
{
for(j=0;j<c2;j++)
{
System.out.print(b[i][j]+"\t");
}
System.out.println("");
}
System.out.println("matrix c is");
for(i=0;i<r1;i++)
{
for(j=0;j<c2;j++)
{
System.out.print(c[i][j]+"\t");
}
System.out.println("");
}
}
else
System.out.println("matrix can't be multiplied");
}
};