/*
  c1 c3 - c2^2
  = (p1 + p2) (p1 z1^2 + p2 z2^2) - (p1 z1 + p2 z2)^2
  = p1 p2 z1^2 + p1 p2 z^2 - 2 p1 p2 z1 z2
  = p1 p2 (z1 - z2)^2
  
  c1 c4 - c2 c3
  = (p1 + p2) (p1 z1^3 + p2 z2^3) - (p1 z1 + p2 z2) (p1 z1^2 + p2 z2^2)
  = p1 p2 z1^3 + p1 p2 z2^3 - p1 p2 z1^2 z2 - p1 p2 z1 z2^2
  = p1 p2 (z1 - z2)^2 (z1 + z2)
  
  c2 c4 - c3^2
  = (p1 z1 + p2 z2) (p1 z1^3 + p2 z2^3) - (p1 z1^2 + p2 z2^2)^2
  = p1 p2 z1^3 z2 + p1 p2 z1 z2^3 - 2 p1 p2 z1^2 z2^2
  = p1 p2 (z1 - z2)^2 (z1 z2)
*/

import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.complex, std.container, std.math, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }




void main() {
  try {
    for (; ; ) {
      const C1 = readLong();
      const C2 = readLong();
      const C3 = readLong();
      const C4 = readLong();
      
      const a = C1 * C3 - C2 * C2;
      const b = C1 * C4 - C2 * C3;
      const c = C2 * C4 - C3 * C3;
      const det = b * b - 4 * a * c;
      writeln((det >= 0) ? "R" : "I");
    }
  } catch (EOFException e) {
  }
}