//<body onKeyDown=K=event.keyCode>
//<script>
X = [Z = [B = A = 12]];
h = e = K = t = P = 0;
function Y () {
C = [d = K - 38];
c = 0;
for (i = 4; i-- * K; K - 13 ? c += !Z[h + p + d] : c -= !Z[h + (C[i] = p * A - Math.round (p / A) * 145)]) {
p = B[i];
}
!t | c + 4 ? c - 4 ? 0 : h += d : B = C;
for (f = K = i = 0; i < 4; f += Z[A + p]) {
X[p = h + B[i++]] = 1;
}