private int[] bigInt(int[] a, int[] b, int expo) {
    if(n1==1)
    {
        result=multiply(a[a.length-1],b[a.length-1]);
        if(expo!=0)
            result=exponential(result,expo);
    }
    else
    {
        int A1[]=divideArray(a,0,n1/2);
        int A2[]=divideArray(a,n1/2,n1);
        int B1[]=divideArray(b,0,n2/2);
        int B2[]=divideArray(b,n2/2,n2);
        int tempA[]=bigInt(A1,B1,0);
        int A[]=exponential(tempA, n1);

        int[] addB=addArray(B1,B2);
        int[] addA=addArray(A1,A2);
        int Byet[]=bigInt(addA,addB,0);
        int C[]=bigInt(A2,B2,0);
        int B[]=subArray(Byet,tempA,C,n1/2);

        result=addArray(A,addArray(B,C));
    }

    return result;
}