func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long INF = 1e9;   const long long MD = 1e9 + 7;   const double pi = acos(-1);   struct segmentTree {     long long tl = 1, tr = (1ll << 21);     segmentTree* left = nullptr;     segmentTree* right = nullptr;     long long val = 0;     segmentTree(long long tl, long long tr) : tl(tl), tr(tr) {}     segmentTree() = default;     void createSons() {       long long tm = (tl + tr) / 2;       if (!left) {         left = new segmentTree(tl, tm);       }       if (!right) {         right = new segmentTree(tm + 1, tr);       }     }     void update(long long pos, long long val) {       if (tl == tr) {         this->val = val;         return;       }       long long tm = (tl + tr) / 2;       createSons();       if (pos <= tm) {         left->update(pos, val);       } else {         right->update(pos, val);       }       this->val = (left->val) ^ (right->val);     }     long long get(long long l, long long r) {       if (l > r) {         return 0;       }       if (l == tl && tr == r) {         return val;       }       long long tm = (tl + tr) / 2;       createSons();       return (left->get(l, min(r, tm))) ^ (right->get(max(tm + 1, l), r));     }   };   ostream& operator<<(ostream& stream, const vector<long long>& v) {     for (auto i : v) {       stream << i <<   n ;     }     return stream;   }   pair<long long, long long> operator+=(pair<long long, long long>& a,                                         const pair<long long, long long>& b) {     a.first += b.first;     a.second += b.second;     return a;   };   long long sqr(long long a) { return a * a % MD; }   long long binpow(long long a, long long b) {     if (b == 0) {       return 1;     }     if (b % 2 == 0) {       return sqr(binpow(a, b / 2));     }     return a * binpow(a, b - 1) % MD;   }   long long fact(long long a) {     long long res = 1;     for (long long i = 2; i <= a; i++) {       res *= i;       res %= MD;     }     return res;   }   struct edge {     long long u, v, c;     bool operator<(const edge& other) const {       if (c == other.c) {         if (u == other.u) {           return v < other.v;         }         return u < other.u;       }       return c < other.c;     }   };   struct query {     long long u, v, k, ind;     bool operator<(const query& other) const {       if (k == other.k) {         if (u == other.u) {           if (ind == other.ind) {             return ind < other.ind;           }           return v < other.v;         }         return u < other.u;       }       return k < other.k;     }   };   vector<long long> g[100006];   long long timer = 1;   long long subTreeSize[100006];   long long pred[100006];   long long tIn[100006];   long long tOut[100006];   void dfs(long long v) {     tIn[v] = timer++;     subTreeSize[v] = 1;     for (auto i : g[v]) {       if (!tIn[i]) {         pred[i] = v;         dfs(i);         subTreeSize[v] += subTreeSize[i];       }     }     tOut[v] = timer++;   }   bool isPred(long long a, long long b) {     return (tIn[a] <= tIn[b] && tOut[b] <= tOut[a]);   }   long long chainNumOfVertex[100006], inChainPositionOfVertex[100006],       chainSize[100006], chainRoot[100006], chainsCount;   vector<segmentTree> segmTrees;   struct HLD {     void build(long long v, long long chainNum) {       chainNumOfVertex[v] = chainNum;       inChainPositionOfVertex[v] = chainSize[chainNum];       chainSize[chainNum]++;       if (chainSize[chainNum] == 1) {         chainRoot[chainNum] = v;       }       long long maxChild = -1;       for (auto i : g[v]) {         if (i != pred[v] &&             (maxChild == -1 || subTreeSize[i] > subTreeSize[maxChild])) {           maxChild = i;         }       }       if (maxChild != -1) {         for (auto i : g[v]) {           if (i == pred[v]) {             continue;           }           if (i == maxChild) {             build(i, chainNum);           } else {             segmTrees.push_back(segmentTree());             build(i, ++chainsCount);           }         }       }     }     long long get(long long a, long long b) {       long long res = 0;       for (long long i = 1; i <= 2; i++) {         while (1) {           if (isPred(chainRoot[chainNumOfVertex[a]], b)) {             break;           }           segmTrees[chainNumOfVertex[a]].tl = 0;           segmTrees[chainNumOfVertex[a]].tr = chainSize[chainNumOfVertex[a]];           res ^=               segmTrees[chainNumOfVertex[a]].get(0, inChainPositionOfVertex[a]);           a = pred[chainRoot[chainNumOfVertex[a]]];         }         swap(a, b);       }       if (inChainPositionOfVertex[a] > inChainPositionOfVertex[b]) {         swap(a, b);       }       segmTrees[chainNumOfVertex[a]].tl = 0;       segmTrees[chainNumOfVertex[a]].tr = chainSize[chainNumOfVertex[a]];       res ^= segmTrees[chainNumOfVertex[a]].get(inChainPositionOfVertex[a] + 1,                                                 inChainPositionOfVertex[b]);       return res;     }     void update(long long a, long long val) {       segmTrees[chainNumOfVertex[a]].tl = 0;       segmTrees[chainNumOfVertex[a]].tr = chainSize[chainNumOfVertex[a]];       segmTrees[chainNumOfVertex[a]].update(inChainPositionOfVertex[a], val);     }     void add(edge e) {       if (pred[e.u] == e.v) {         update(e.u, e.c);       } else {         update(e.v, e.c);       }     }   };   signed main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     long long t;     cin >> t;     while (t--) {       long long n;       cin >> n;       string st;       cin >> st;       st =  0  + st;       long long ans = 0;       for (long long i = 1; i < st.size(); i++) {         if (st[i] ==  1 ) {           ans = max(2 * i, ans);           ans = max((n - i + 1) * 2, ans);         }       }       cout << max(ans, n) <<   n ;     }   }   