var x = s[i].split(' ');

switch (x.length) {
    case 1: x[1] = x[2] = x[3] = x[0]; break;
    case 2: x[2] = x[0]; x[3] = x[1]; break;
    case 3: x[3] = x[1]; break;
}

return {
    top   : parseInt(x[0],10),
    right : parseInt(x[1],10),
    bottom: parseInt(x[2],10),
    left  : parseInt(x[3],10)
};