diff --git a/index.ts b/index.ts
index cd7615c7..aab54a1b 100644
--- a/index.ts
+++ b/index.ts
@@ -1,11 +1,12 @@
 import { Drug, Pharmacy } from "./pharmacy";
+import { Linear, DoubleAfterExpires, Reverse, ChangeAcrossExpires, ZeroAfterExpires, Double } from "./revaluations";
 
 import fs from "fs";
 
 const drugs = [
-  new Drug("Doliprane", 20, 30),
-  new Drug("Herbal Tea", 10, 5),
-  new Drug("Fervex", 5, 40),
+  new Drug("Doliprane", 20, 30, [new Linear(), new DoubleAfterExpires()]),
+  new Drug("Herbal Tea", 10, 5, [new Linear(), new DoubleAfterExpires(), new Reverse()]),
+  new Drug("Fervex", 5, 40, [new Linear(), new ChangeAcrossExpires(), new Reverse(), new ZeroAfterExpires()]),
   new Drug("Magic Pill", 15, 40)
 ];
 const trial = new Pharmacy(drugs);
diff --git a/pharmacy.ts b/pharmacy.ts
index 6a527b65..f9102001 100644
--- a/pharmacy.ts
+++ b/pharmacy.ts
@@ -81,60 +81,17 @@ export class Drug implements DrugData {
   }
 }
 export class Pharmacy {
-  constructor(public drugs = []) {
-    this.drugs = drugs;
+  constructor(private _drugs: Drug[] = []) {}
+
+  public get drugs(): Drug[] {
+    return [...this._drugs];
   }
-  updateBenefitValue() {
-    for (var i = 0; i < this.drugs.length; i++) {
-      if (
-        this.drugs[i].name != "Herbal Tea" &&
-        this.drugs[i].name != "Fervex"
-      ) {
-        if (this.drugs[i].benefit > 0) {
-          if (this.drugs[i].name != "Magic Pill") {
-            this.drugs[i].benefit = this.drugs[i].benefit - 1;
-          }
-        }
-      } else {
-        if (this.drugs[i].benefit < 50) {
-          this.drugs[i].benefit = this.drugs[i].benefit + 1;
-          if (this.drugs[i].name == "Fervex") {
-            if (this.drugs[i].expiresIn < 11) {
-              if (this.drugs[i].benefit < 50) {
-                this.drugs[i].benefit = this.drugs[i].benefit + 1;
-              }
-            }
-            if (this.drugs[i].expiresIn < 6) {
-              if (this.drugs[i].benefit < 50) {
-                this.drugs[i].benefit = this.drugs[i].benefit + 1;
-              }
-            }
-          }
-        }
-      }
-      if (this.drugs[i].name != "Magic Pill") {
-        this.drugs[i].expiresIn = this.drugs[i].expiresIn - 1;
-      }
-      if (this.drugs[i].expiresIn < 0) {
-        if (this.drugs[i].name != "Herbal Tea") {
-          if (this.drugs[i].name != "Fervex") {
-            if (this.drugs[i].benefit > 0) {
-              if (this.drugs[i].name != "Magic Pill") {
-                this.drugs[i].benefit = this.drugs[i].benefit - 1;
-              }
-            }
-          } else {
-            this.drugs[i].benefit =
-              this.drugs[i].benefit - this.drugs[i].benefit;
-          }
-        } else {
-          if (this.drugs[i].benefit < 50) {
-            this.drugs[i].benefit = this.drugs[i].benefit + 1;
-          }
-        }
-      }
+
+  updateBenefitValue(): Drug[] {
+    for (const drug of this._drugs) {
+      drug.benefitRevaluate();
     }
 
-    return this.drugs;
+    return [...this._drugs];
   }
 }