#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = uint32_t;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;

int main() {
    ll a, b, c, d;
    cin >> a >> b >> c >> d;
    puts((a*d-b*c)*(a*d-b*c) >= 4*(a*c-b*b)*(b*d-c*c)? "R" : "I");
    return 0;
}