int exponentiate(bn_t base,bn_t exponent,bn_t result){
  int size=get_bn_size(exponent);
  char buffer[size];
  bn_t tempRemainder = bn_alloc();
  bn_t tempDenominator=bn_alloc();
  bn_t tempRes=bn_alloc();
  bn_t tempExponent=bn_alloc();
  bn_fromString(tempDenominator,"2");
  bn_t one=bn_alloc();
  bn_fromString(one,"1");

  if(!strncmp(buffer, "0",size)){
    bn_fromString(result, "1");
  }

  else if(!strncmp(buffer,"1",size)){
    bn_toString(base,buffer,size);
    bn_fromString(result,buffer);
  }
  else if(base->bn_data[0]%2==0){
    //calculate for even bn
    bn_mul(result, base, base);
    bn_div(tempExponent,tempRemainder,exponent,tempDenominator);
    printf("%s%d\n","EVEN NUMBER ",tempExponent->bn_data[0]);
    bn_toString(tempExponent,buffer,size);
    bn_fromString(exponent,buffer);
    bn_free(tempDenominator);
    bn_free(tempRemainder);
    bn_free(tempExponent);
    exponentiate(result,result,exponent);

  }
  else if(base->bn_data[0]%2==1){
    bn_mul(tempRes, base, base);
    bn_sub(tempExponent,exponent,one);
    bn_div(tempExponent,tempRemainder,exponent,tempDenominator);
    printf("%s%d\n","ODD NUMBER ",tempExponent->bn_data[0]);
    bn_toString(tempExponent,buffer,size);
    bn_fromString(exponent,buffer);
    bn_free(tempDenominator);
    bn_free(tempRemainder);
    bn_free(one);
    bn_free(tempExponent);
    //calculate for odd bn
    exponentiate(result,result,exponent);
    bn_mul(result,tempRes,result);
  }

  return 0;
}