diff --git "a/khj20006/202508/08 BOJ P3 \354\235\274\352\270\260\354\230\210\353\263\264.md" "b/khj20006/202508/08 BOJ P3 \354\235\274\352\270\260\354\230\210\353\263\264.md"
new file mode 100644
index 00000000..29bbf30a
--- /dev/null
+++ "b/khj20006/202508/08 BOJ P3 \354\235\274\352\270\260\354\230\210\353\263\264.md"	
@@ -0,0 +1,60 @@
+```cpp
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+using namespace std;
+using namespace __gnu_pbds;
+
+using ll = long long;
+using pbds = tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>;
+
+pbds os;
+ll a[100001]{};
+int N, M;
+
+void remove(ll v) {
+	os.erase(os.find_by_order(os.order_of_key(v)));
+}
+
+int main(){
+	cin.tie(0)->sync_with_stdio(0);
+
+	cin>>N>>M;
+	for(int i=1;i<=N;i++) {
+		cin>>a[i];
+		os.insert(a[i]);
+	}
+
+	for(;M--;) {
+		int o;
+		cin>>o;
+		if(o <= 2) {
+			int i;
+			ll x;
+			cin>>i>>x;
+			x *= o == 1 ? 1 : -1;
+			remove(a[i]);
+			a[i] += x;
+			os.insert(a[i]);
+		}
+		else if(o == 3) {
+			ll l, r;
+			cin>>l>>r;
+			cout<<os.order_of_key(r+1) - os.order_of_key(l)<<'\n';
+		}
+		else {
+			int t;
+			cin>>t;
+			t = N-t+1;
+			ll s = 0, e = 2e15, m = (s+e+1)>>1;
+			while(s<e) {
+				if(os.order_of_key(m) < t) s = m;
+				else e = m-1;
+				m = (s+e+1)>>1;
+			}
+			cout<<m<<'\n';
+		}
+	}
+
+}
+```