Cannot sample enough valid points. (more)

\[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\]
\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)
double f(double x, double y, double z, double t) {
        double r365305 = x;
        double r365306 = 1.0;
        double r365307 = r365305 + r365306;
        double r365308 = sqrt(r365307);
        double r365309 = sqrt(r365305);
        double r365310 = r365308 - r365309;
        double r365311 = y;
        double r365312 = r365311 + r365306;
        double r365313 = sqrt(r365312);
        double r365314 = sqrt(r365311);
        double r365315 = r365313 - r365314;
        double r365316 = r365310 + r365315;
        double r365317 = z;
        double r365318 = r365317 + r365306;
        double r365319 = sqrt(r365318);
        double r365320 = sqrt(r365317);
        double r365321 = r365319 - r365320;
        double r365322 = r365316 + r365321;
        double r365323 = t;
        double r365324 = r365323 + r365306;
        double r365325 = sqrt(r365324);
        double r365326 = sqrt(r365323);
        double r365327 = r365325 - r365326;
        double r365328 = r365322 + r365327;
        return r365328;
}