def sign(a):
    return a/abs(a) if a != 0 else 0

c1, c2, c3, c4 = map(int, raw_input().split())
d1 = c1*c3 - c2*c2
d2 = c2*c4 - c3*c3
if sign(d1) != sign(d2):
    print "R"
else:
    print "I"