#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
#define ins insert

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int MOD = 1000000007;
const char nl = '\n';
const int MX = 100001; //check the limits, dummy

void solve() {
    ll X, Y; cin >> X >> Y;
    string ans = "";
    F0Rd(cap, 36) {
        ll A = X, B = Y;
        string cur = "";
        F0Rd(i, cap) {
            if (abs(A) > abs(B) && A > 0) {
                cur += 'E';
                A -= (1ll << i);
            } else if (abs(A) > abs(B) && A < 0) {
                cur += 'W';
                A += (1ll << i);
            } else if (B > 0) {
                cur += 'N';
                B -= (1ll << i);
            } else {
                cur += 'S';
                B += (1ll << i);
            }
        }
        if (A == 0 && B == 0) {
            reverse(all(cur)); ans = cur;
        }
    }
    if (ans == "") {
        cout << "IMPOSSIBLE" << nl;
    } else {
        cout << ans << nl;
    }
}

int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);

    int T; cin >> T;
    FOR(i, 1, T+1) {
        cout << "Case #" << i << ": ";
        solve();
    }

	return 0;
}

// read the question correctly (ll vs int)
// template by bqi343