#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
//#include<cctype>
#include<climits>
#include<iostream>
#include<string>
#include<vector>
#include<map>
//#include<list>
#include<queue>
#include<deque>
#include<algorithm>
//#include<numeric>
#include<utility>
#include<complex>
//#include<memory>
#include<functional>
#include<cassert>
#include<set>
#include<stack>

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int, int> pii;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll c1, c2, c3, c4;
    cin >> c1 >> c2 >> c3 >> c4;
    assert(-5000 <= c1 && c1 <= 5000);
    assert(-5000 <= c2 && c2 <= 5000);
    assert(-5000 <= c3 && c3 <= 5000);
    assert(-5000 <= c4 && c4 <= 5000);
    ll a = c1*c4-c2*c3;
    ll b = (c3*c1-c2*c2) * (c3*c3-c2*c4);
    assert(a*a+4*b != 0);
    if (a*a+4*b > 0) cout << "R" << endl;
    else cout << "I" << endl;
    return 0;
}