diff --git a/exo4.py b/exo4.py
index cd9ac48..bc7733e 100644
--- a/exo4.py
+++ b/exo4.py
@@ -1,5 +1,56 @@
+import sys
+
+ROCK = "rock"
+SPICE = "spice"
+
+
 def main():
-    pass
+    lines = []
+    for line in sys.stdin:
+        lines.append(line.rstrip("\n"))
+
+    number_of_rocks, number_of_spices_types, capacity = map(int, lines[0].split())
+    rocks = []
+    spices = []
+    for line in lines[1 : number_of_rocks + 1]:
+        value, weight = map(int, line.split())
+        rocks.append(
+            {
+                "type": ROCK,
+                "total_value": value,
+                "weight": weight,
+                "cost_per_gram": value / weight,
+            }
+        )
+    for line in lines[number_of_rocks + 1 :]:
+        cost_per_gram, weight = map(int, line.split())
+        spices.append(
+            {
+                "type": SPICE,
+                "total_value": cost_per_gram * weight,
+                "weight": weight,
+                "cost_per_gram": cost_per_gram,
+            }
+        )
+    items = []
+    items.extend(rocks)
+    items.extend(spices)
+    items.sort(key=lambda x: x["cost_per_gram"], reverse=True)
+
+    cash_prize = 0
+    for item in items:
+        if item["type"] == ROCK and capacity - item["weight"] >= 0:
+            cash_prize += item["total_value"]
+            capacity -= item["weight"]
+        elif item["type"] == SPICE:
+            taking = min(capacity, item["weight"])
+            cash_prize += item["cost_per_gram"] * taking
+            capacity -= taking
+        if capacity == 0:
+            print(cash_prize)
+            return
+    print(cash_prize)
+    return
 
 
 if __name__ == "__main__":