diff --git a/atcoder/abc083/A/main.cpp b/atcoder/abc083/A/main.cpp
new file mode 100644
index 00000000..78016f3a
--- /dev/null
+++ b/atcoder/abc083/A/main.cpp
@@ -0,0 +1,22 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    int A, B, C, D;
+    cin >> A >> B >> C >> D;
+    int L = A + B, R = C + D;
+    if (L > R) {
+        cout << "Left" << endl;
+    } else if (L < R) {
+        cout << "Right" << endl;
+    } else {
+        cout << "Balanced" << endl;
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/atcoder/abc083/B/main.cpp b/atcoder/abc083/B/main.cpp
index 66e82e06..9beaee1a 100644
--- a/atcoder/abc083/B/main.cpp
+++ b/atcoder/abc083/B/main.cpp
@@ -1,35 +1,36 @@
 #include <bits/stdc++.h>
 
 using namespace std;
+using ll = long long;
 
-int digsum(int V) {
-    int sum = 0;
-    while (V > 0)
-    {
-        sum += V % 10;
-        V /= 10;
+int N, A, B;
+
+int digsum(int m) {
+    int s = 0;
+    while (m > 0) {
+        s += m % 10;
+        m /= 10;
     }
-    return sum;
+    return s;
 }
 
-int solve(int N, int A, int B) {
-    int ans = 0;
+int solve() {
+    int sum = 0;
     for (int i = 1; i <= N; ++i) {
-        int sum = digsum(i);
-        if (sum >= A && sum <= B) {
-            ans += i;
+        int ds = digsum(i);
+        if (ds >= A && ds <= B) {
+            sum += i;
         }
     }
-    return ans;
+    return sum;
 }
 
 int main() {
     ios_base::sync_with_stdio(false);
     cin.tie(0); cout.tie(0);
 
-    int N, A, B;
     cin >> N >> A >> B;
-    cout << solve(N, A, B) << endl;
+    cout << solve() << endl;
 
     return 0;
 }
\ No newline at end of file
diff --git a/atcoder/abc083/C/main.cpp b/atcoder/abc083/C/main.cpp
new file mode 100644
index 00000000..3fde3060
--- /dev/null
+++ b/atcoder/abc083/C/main.cpp
@@ -0,0 +1,20 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    ll X, Y;
+    cin >> X >> Y;
+    int len = 1;
+    while (X * 2 <= Y) {
+        ++len;
+        X *= 2;
+    }
+    cout << len << endl;
+
+    return 0;
+}
\ No newline at end of file
diff --git a/atcoder/abc083/D/main.cpp b/atcoder/abc083/D/main.cpp
new file mode 100644
index 00000000..94dc41dc
--- /dev/null
+++ b/atcoder/abc083/D/main.cpp
@@ -0,0 +1,27 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int solve(string& S) {
+    const int N = S.size();
+    int ans = N;
+    for (int i = 0; i + 1 < N; ++i) {
+        if (S[i] != S[i+1]) {
+            int m = max(i+1,N-(i+1));
+            ans = min(ans, m);
+        }
+    }
+    return ans;
+}
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    string S;
+    cin >> S;
+    cout << solve(S) << endl;
+
+    return 0;
+}
\ No newline at end of file