recursive.js

var depth = 1, invocations = 0, substractions = 0, edge = 0;

function f(x, y, z) {
  if(y < x) {
    // Increment the counters
    ++depth
    substractions += 3
    if(depth > edge) edge = depth
    console.log("Recursion depth: %d", depth)
    
    z = f(f(x - 1, y, z), f(y - 1, z, x), f(z - 1, x, y))
    
    // We are back
    --depth
  }
  return z
}

var x = 18, y = 12, z = 6

f(x, y, z)
console.log("Maximum recursion depth: %d", edge)