C++|| SET|| Easy
\nclass LUPrefix {\npublic:\n    set<int>st;\n    LUPrefix(int n) {\n        for(int i=1;i<=n+1;i++){\n            st.insert(i);\n        }\n    }\n    \n    vo
```\nclass LUPrefix {\npublic:\n    set<int>st;\n    LUPrefix(int n) {\n        for(int i=1;i<=n+1;i++){\n            st.insert(i);\n        }\n    }\n    \n    void upload(int video) {\n        st.erase(video);\n    }\n    \n    int longest() {\n        return (*st.begin())-1;\n    }\n};\n```
['C', 'Ordered Set']