A weak return with dev c++

#include <iostream>
#include <stdlib.h>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

using namespace std;

int main(int argc, char** argv) {

    cout << "Hello my name is Felix and i'm the best" << endl;

    int rand_num = rand() % 20 + 1;
    int user_guess;

    do
    {
    cout << "Guess number between 1 to 20: ";
    cin >> user_guess;

    if(user_guess == rand_num)
    {
        cout << "you guessed it right!" << endl;
    }

    }while(user_guess != rand_num);

    system("pause");

    return 0;
}