diff --git a/Codeforces/800ranting/dislike_of_threes.cpp b/Codeforces/800ranting/dislike_of_threes.cpp
new file mode 100644
index 0000000..338cfb0
--- /dev/null
+++ b/Codeforces/800ranting/dislike_of_threes.cpp
@@ -0,0 +1,31 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+const int MAX = 1e3+10;
+vector<int> sequence(MAX);
+
+void init_seq() {
+
+    int aux = 1;
+    for(int i = 0; i < MAX; ++i) {
+        while(aux%3==0 or (aux%10)==3) 
+            aux++;
+        sequence[i] = aux;
+        aux++;
+    }
+
+}
+
+int main(){
+
+    init_seq();
+    int t; cin >> t;
+    while(t--) {
+        int a; cin >> a;
+        cout << sequence[a-1] << endl;
+    }
+
+    return 0;
+
+}
+
diff --git a/Codeforces/800ranting/fair_playoff.cpp b/Codeforces/800ranting/fair_playoff.cpp
new file mode 100644
index 0000000..b530eb6
--- /dev/null
+++ b/Codeforces/800ranting/fair_playoff.cpp
@@ -0,0 +1,31 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+
+int main(){
+
+    int t; cin >> t;
+    while(t--) {
+        int bigger = 0, bigger2 = 0;
+        vector<int> nums(4);
+        for(int i = 0; i < 4; ++i) {
+            cin >> nums[i];
+            if(nums[i] >= bigger) {
+                int aux = bigger;
+                bigger = nums[i];
+                bigger2 = aux;
+            }
+
+            if(nums[i] != bigger and nums[i] > bigger2)
+                bigger2 = nums[i];
+        }
+
+        if((nums[0] == bigger and nums[1] == bigger2) or (nums[1] == bigger and nums[0] == bigger2) or (nums[2] == bigger and nums[3] == bigger2) or (nums[3] == bigger and nums[2] == bigger2))
+            cout << "NO" << endl;
+        else
+            cout << "YES" << endl;    
+    }
+
+    return 0;
+
+}
\ No newline at end of file
diff --git a/Codeforces/800ranting/odd_set.cpp b/Codeforces/800ranting/odd_set.cpp
new file mode 100644
index 0000000..cd762c0
--- /dev/null
+++ b/Codeforces/800ranting/odd_set.cpp
@@ -0,0 +1,22 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+
+int main(){
+
+    int n; cin >> n;
+    while(n--) {
+        int t; cin >> t;
+        int countEven = 0, countOdd = 0;
+        for(int i = 0; i < 2*t; i++) {
+            int num; cin >> num;
+            if(num&1)
+                countOdd++;
+            else
+                countEven++;
+        }
+        cout << (countEven==countOdd?"Yes":"No") << endl;
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Codeforces/800ranting/polycarp_coins.cpp b/Codeforces/800ranting/polycarp_coins.cpp
new file mode 100644
index 0000000..72ab5f5
--- /dev/null
+++ b/Codeforces/800ranting/polycarp_coins.cpp
@@ -0,0 +1,22 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+
+int main(){
+
+    int n; cin >>n;
+    while(n--) {
+        int t; cin >> t;
+        if(t%3) {
+            if(t/3+2*((t/3)+1) == t)
+                cout << t/3 << " " << t/3+1 << endl;
+            else
+                cout << t/3+1 << " " << t/3 << endl;    
+        } else
+            cout << t/3 << " " << t/3 << endl;
+    }
+
+    return 0;
+
+
+}
\ No newline at end of file