diff --git a/srm_164_div1_300.cpp b/srm_164_div1_300.cpp
new file mode 100644
index 0000000..83e5806
--- /dev/null
+++ b/srm_164_div1_300.cpp
@@ -0,0 +1,86 @@
+#include <vector>
+#include <string>
+using namespace std;
+
+class UserId {
+public:
+	bool isValidChar(string name) {
+		for (int i = 0; i < name.size(); i++) {
+			if (isalpha(name[i])) continue;
+			if (name[i] == '\'' || name[i] == ' ') continue;
+			return false;
+		}
+		return true;
+	}
+	
+	string extract(string name) {
+		string res = "";
+		for (int i = 0; i < name.size(); i++) {
+			if (isalpha(name[i])) res += tolower(name[i]);
+		}
+		return res;
+	}
+	
+	bool findInUse(vector<string> inUse, string name) {
+		for (int i = 0; i < inUse.size(); i++)
+			if (inUse[i] == name) return true;
+		return false;
+	}
+	
+	string int2digit(int x) {
+		string res = "";
+		res += x/10 + '0';
+		res += x%10 + '0';
+		return res;
+	}
+	
+	string rule1Id(string first, string last) {
+		string res = first[0] + last;
+		if (res.size() > 8) res = res.substr(0, 8);
+		return res;
+	}
+	
+	string rule2Id(string first, string middle, string last) {
+		string res = "";
+		res += first[0];
+		res += middle[0];
+		res += last;
+		if (res.size() > 8) res = res.substr(0, 8);
+		return res;
+	}
+	
+	string rule3Id(string first, string last, int index) {
+		string res = "";
+		res += first[0];
+		res += last;
+		res = res.substr(0, 6);
+		return res + int2digit(index);
+	}
+	
+	bool checkValidChar(string first, string middle, string last) {
+		if (!isValidChar(first) || !isValidChar(middle) || !isValidChar(last)) return false;
+		return true;
+	}
+	
+	string id(vector <string> inUse, string first, string middle, string last) {
+		if (!checkValidChar(first, middle, last)) return "BAD DATA";
+		first = extract(first);  middle = extract(middle);  last = extract(last);
+		if (first.size() < 2 || last.size() < 2) return "BAD DATA";
+		
+		//first rule
+		string rule1 = rule1Id(first, last);
+		if (!findInUse(inUse, rule1)) return rule1;
+		
+		//second rule
+		if (middle.size() > 0) {
+			string rule2 = rule2Id(first, middle, last);
+			if (!findInUse(inUse, rule2)) return rule2;
+		}
+		
+		//third rule
+		for (int i = 1; i <= 99; i++) {
+			string rule3 = rule3Id(first, last, i);
+			if (!findInUse(inUse, rule3)) return rule3;
+		}
+	}
+};