diff --git a/playcodonv/Solution.java b/playcodonv/Solution.java
new file mode 100644
index 0000000..a7d5309
--- /dev/null
+++ b/playcodonv/Solution.java
@@ -0,0 +1,54 @@
+package A0331;
+
+import java.util.StringTokenizer;
+
+public class Solution {
+
+	public static void main(String[] args) {
+		String[] id_list= {"con", "ryan"};
+		String[] report = {"ryan con", "ryan con", "ryan con", "ryan con"};
+		int[][] check = new int[id_list.length][id_list.length];
+		int k = 3;
+		int[] stop = new int[id_list.length];
+		int[] answer = new int[id_list.length];
+		
+		for(int i = 0;i<report.length;i++) {
+			StringTokenizer st = new StringTokenizer(report[i]," ");
+			String one = st.nextToken();
+			String two = st.nextToken();
+			//System.out.println(one+ " "+two);	
+			int police =  0; //신고한사람 idx
+			int thief = 0; //신고 당한사람 idx
+			for (int j = 0; j < id_list.length; j++) {
+				if(id_list[j].equals(one)) police = j;
+				if(id_list[j].equals(two)) thief = j;
+			}
+			check[police][thief] = 1;
+		}
+		
+		for(int i = 0;i< id_list.length;i++) {
+			for(int j = 0;j< id_list.length;j++) {
+				if(check[j][i] == 1) stop[i] ++;
+			}
+		}
+		/*for(int i =0;i<stop.length;i++) {
+			System.out.print(stop[i]+" ");
+		}
+		
+		System.out.println("");*/
+		
+		
+		for(int i = 0;i<id_list.length;i++) {
+			for(int j = 0;j<id_list.length;j++) {
+				if(stop[j] >= k && check[i][j] == 1) {
+					answer[i]++;
+				}
+			}
+		}
+		/*for(int i =0;i<stop.length;i++) {
+			System.out.print(answer[i]+" ");
+		}*/
+		
+	}
+
+}
diff --git a/playcodonv/Solution2.java b/playcodonv/Solution2.java
new file mode 100644
index 0000000..43c4b91
--- /dev/null
+++ b/playcodonv/Solution2.java
@@ -0,0 +1,50 @@
+package A0331;
+
+import java.util.*;
+import java.io.*;
+
+public class Solution2 {
+	
+
+	public static void main(String[] args) throws Exception{
+		int n = 1000000;
+		int k = 3;
+		String change="";
+		int answer = 0;
+		//진법변환
+			
+			change = Integer.toString(n, k);
+		//	change = "";
+			change += '0';
+			
+			String sector = "";
+			for(int i = 0; i<change.length();i++) {
+				if(change.charAt(i) != '0')  sector += change.charAt(i);
+				else {
+					//Integer.parseInt(sector);
+					//System.out.println(sector);
+					int temp = Integer.parseInt(sector);
+					//System.out.println(temp);
+					sector = "0"; //null 대신에 이걸 넣어줘야함 
+					if(isPrime(temp)) {
+						answer ++;
+					}
+					else continue;
+				}
+			}
+			System.out.println(answer);
+				
+	}
+	static boolean isPrime(long number) {
+		
+		if(number == 0) return false;
+		if(number == 1) return false;
+		if(number == 2) return true;
+		for(int i = 3; i<=Math.sqrt(number); i = i+2) {
+			if(number % i == 0) return false;
+		}
+		return true;
+	}
+	
+
+}