How to store data in RTC internal memory of ESP8266 thing dev board ?

I am using the code below to read and write the data stored in esp8266 internal rtc memory:

#include <ESP8266WiFi.h>

const unsigned long SLEEP_INTERVAL = 10 * 1000 * 1000; // 20 sec

extern "C" {
#include "user_interface.h"
}

void setup() {
Serial.begin(74880);
Serial.println();

Serial.println("RTC Memory Test");

byte rtcStore[2];
system_rtc_mem_read(65, rtcStore, 2); //offset is 65

Serial.print("current value = ");
Serial.println(*rtcStore);

(*rtcStore)++; //increment the value
Serial.print("new value = ");
Serial.println(*rtcStore);

system_rtc_mem_write(65, rtcStore, 2); //offset is 65

//sleep modes: WAKE_RF_DEFAULT, WAKE_RFCAL, WAKE_NO_RFCAL,
WAKE_RF_DISABLED
ESP.deepSleep(SLEEP_INTERVAL - micros(), WAKE_RF_DISABLED);

delay(1000);
}

void loop() {
// should never get here
}
When I upload the code and open serial monitor, value of rtcCounter starts from 109. However, I want to store some other value like 4,3, 0 etc. How can I store particular value in rtcStore ? Thank You!!