package no328;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		//実質writer解丸写しです(◞‸◟)
		Scanner sc = new Scanner(System.in);
		long c1 = sc.nextLong();
		long c2 = sc.nextLong();
		long c3 = sc.nextLong();
		long c4 = sc.nextLong();
		long a = c1*c4 - c2*c3;
		long b = (c3*c1 - c2*c2) * (c3*c3 - c2*c4);
		System.out.println(a*a+4*b>0 ? "R" : "I");
	}

}