diff --git a/HYUNSOO/BOJ/BOJ_13305.java b/HYUNSOO/BOJ/BOJ_13305.java
new file mode 100644
index 0000000..3581e90
--- /dev/null
+++ b/HYUNSOO/BOJ/BOJ_13305.java
@@ -0,0 +1,52 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+class Main {
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+
+        int cityNumber = Integer.parseInt(bufferedReader.readLine());
+
+        int[] nextDistance = new int[cityNumber];
+        int[] oilCost = new int[cityNumber];
+
+        StringTokenizer tokenizer = new StringTokenizer(bufferedReader.readLine());
+        for (int i = 0; i < cityNumber-1; i++) {
+            nextDistance[i] = Integer.parseInt(tokenizer.nextToken());
+        }
+
+        tokenizer = new StringTokenizer(bufferedReader.readLine());
+        for (int i = 0; i < cityNumber; i++) {
+            oilCost[i] = Integer.parseInt(tokenizer.nextToken());
+        }
+
+        long totalCost = getTotalCost(cityNumber, oilCost, nextDistance);
+
+        System.out.println(totalCost);
+    }
+
+    private static long getTotalCost(int cityNumber, int[] oilCost, int[] nextDistance) {
+        long totalCost = 0;
+        for (int i = 0; i < cityNumber; i++) {
+            int cOilCost = oilCost[i];
+            int nextCity = i+1;
+
+            for (; nextCity < cityNumber; nextCity++) {
+                if (cOilCost > oilCost[nextCity]) {
+                    break;
+                }
+            }
+
+            int cNextDistance = 0;
+            for (int j = i; j < nextCity; j++) {
+                cNextDistance += nextDistance[j];
+            }
+
+            totalCost += ((long) cOilCost * cNextDistance);
+            i = nextCity - 1;
+        }
+        return totalCost;
+    }
+}
diff --git a/HYUNSOO/BOJ/BOJ_1541.java b/HYUNSOO/BOJ/BOJ_1541.java
new file mode 100644
index 0000000..8e891b4
--- /dev/null
+++ b/HYUNSOO/BOJ/BOJ_1541.java
@@ -0,0 +1,49 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
+
+class Main {
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        String str = bufferedReader.readLine();
+
+        List<Integer> numbers = new ArrayList<>();
+        List<Character> sign = new ArrayList<>();
+
+        StringBuilder number = new StringBuilder();
+        for (char c : str.toCharArray()) {
+            if (c == '-' || c == '+') {
+                numbers.add(Integer.parseInt(number.toString()));
+                sign.add(c);
+
+                number = new StringBuilder();
+                continue;
+            }
+            number.append(c);
+        }
+        numbers.add(Integer.parseInt(number.toString()));
+
+        int result = numbers.get(0);
+        int sum = 0;
+        for (int i = 1; i < numbers.size(); i++) {
+            if (sign.get(i-1) == '-') {
+                result -= sum;
+                sum = 0;
+                sum += numbers.get(i);
+
+            } else if (sign.get(i-1) == '+') {
+                if (sum == 0) {
+                    result += numbers.get(i);
+                } else {
+                    sum += numbers.get(i);
+
+                }
+            }
+        }
+        result -= sum;
+
+        System.out.println(result);
+    }
+}