#include <bits/stdc++.h>
using namespace std;
using LL = long long;

#define fs first
#define sc second

const LL MOD = 1e9+7;
const double EPS = 1e-10;

template<class T>bool chmax(T &a, const T &b) {
    if (a < b) { a = b; return true; }
    return false;
}
template<class T>bool chmin(T &a, const T &b) {
    if (b < a) { a = b; return true; }
    return false;
}

// std::vector Declaration
template<typename T>
vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts) {
    return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

// std::vector Declaration and Initialization
template<typename T>
vector<T> make_vector(size_t a, T x) { return vector<T>(a, x); }
template<typename T, typename U, typename... Ts>
auto make_vector(size_t a, U b, Ts... ts) {
    return vector<decltype(make_vector<T>(b,ts...))>(a,make_vector<T>(b,ts...));
}

// std::vector Input
template<typename T>
istream& operator>>(istream& is, vector<T>& v) {
    for (auto &e : v) {
        is >> e;
    }
    return is;
}

// std::vector Debug
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    os << "[";
    bool a = 1;
    for (auto e : v) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "]";
    return os;
}

// std::array Debug
template<typename T, size_t n>
ostream& operator<<(ostream& os, const array<T, n>& v) {
    os << "[";
    bool a = 1;
    for (auto e : v) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "]";
    return os;
}

// std::deque Debug
template<typename T>
ostream& operator<<(ostream& os, const deque<T>& d) {
    os << "[";
    bool a = 1;
    for (auto e : d) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "]";
    return os;
}

// std::pair Debug
template<typename T, typename U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
    os << "(" << p.first << " " << p.second << ")";
    return os;
}

// std::set Debug
template<typename T>
ostream& operator<<(ostream& os, const set<T>& st) {
    os << "{";
    bool a = 1;
    for (auto e : st) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "}";
    return os;
}

// std::multiset Debug
template<typename T>
ostream& operator<<(ostream& os, const multiset<T>& st) {
    os << "{";
    bool a = 1;
    for (auto e : st) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "}";
    return os;
}

// std::map Debug
template<typename T, typename U>
ostream& operator<<(ostream& os, const map<T, U>& mp) {
    os << "{";
    bool a = 1;
    for (auto e : mp) {
        os << (a ? "" : " ");
        os << e.first << ":" << e.second;
        a = 0;
    }
    os << "}";
    return os;
}

// std::tuple Debug
template<int N, class Tuple>
void out(ostream& os, const Tuple& t){}
template<int N, class Tuple, class H, class ...Ts>
void out(ostream& os, const Tuple& t) {
    if (N) os << " ";
    os << get<N>(t);
    out<N+1,Tuple,Ts...>(os, t);
}
template<class ...Ts>
ostream& operator<<(ostream& os, const tuple<Ts...>& t) {
    os << "(";
    out<0,tuple<Ts...>,Ts...>(os, t);
    os << ")";
    return os;
}

// Debug
#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl

// Weighted edge
template<typename T>
struct edge {
    int src, to;
    T cost;

    edge(int to, T cost) : src(-1), to(to), cost(cost) {}
    edge(int src, int to, T cost) : src(src), to(to), cost(cost) {}

    edge &operator=(const int &x) {
        to = x;
        return *this;
    }

    operator int() const { return to; }

    friend ostream& operator<<(ostream& os, const edge& e) {
        return os << "(" << e.src << "->" << e.to << ":" << e.cost << ")";
    }
};

template<typename T>
using Edges = vector<edge<T>>;
template<typename T>
using WeightedGraph = vector<Edges<T>>;
using UnWeightedGraph = vector<vector<int>>;
template<typename T>
using MatrixGraph = vector<vector<T>>;

using Matrix = vector<vector<double>>;

pair<Matrix,Matrix> LUDecomposition(const Matrix& A) {
    // A: Squere Matirix
    int n = A.size();
    const double INF = numeric_limits<double>::max();
    Matrix L = make_v<double>(n, n),
           U = make_v<double>(n, n);

    for (int i = 0; i < n; ++i) {
        L[i][i] = 1;
    }

    for (int i = 0; i < n; ++i) {
        // L
        for (int j = 0; j < i; ++j) {
            double total = 0;
            for (int k = 0; k < j; ++k) {
                total += L[i][k] * U[k][j];
            }
            L[i][j] = (A[i][j] - total) / U[j][j];
        }

        // U
        for (int j = i; j < n; ++j) {
            double total = 0;
            for (int k = 0; k < i; ++k) {
                total += L[i][k] * U[k][j];
            }
            U[i][j] = A[i][j] - total;
        }
    }

    return make_pair(L, U);
}

using Vector = vector<double>;

Vector solve(const Matrix& A, const Vector& b) {
    // A: Squere Matrix
    int n = A.size();
    Matrix L, U;
    tie(L, U) = LUDecomposition(A);

    Vector y(n);
    for (int i = 0; i < n; ++i) {
        double total = 0;
        for (int j = 0; j < i; ++j) {
            total += y[j] * L[i][j];
        }
        y[i] = b[i] - total;
    }

    Vector x(n);
    for (int i = n-1; i >= 0; --i) {
        double total = 0;
        for (int j = n-1; j > i; --j) {
            total += U[i][j] * x[j];
        }
        x[i] = (y[i] - total) / U[i][i];
    }

    return x;
}

int main()
{
    while (true) {
        int d; cin >> d;
        if (d == 0) {
            break;
        }

        vector<double> v(d+3); cin >> v;
        vector<double> ans(d+3);

        for (int m = 0; m < d+3; ++m) {

            int check = (d+1+m) % (d+3);

            Matrix A = make_v<double>(d+1, d+1);
            for (int i = 0; i <= d; ++i) {
                for (int k = 0; k <= d; ++k) {
                    A[i][k] = pow((i+m) % (d+3), k);
                }
            }

            Vector b(d+1);
            for (int i = 0; i <= d; ++i) {
                b[i] = v[(i+m) % (d+3)];
            }

            Vector a = solve(A, b);

            double sum = 0;
            for (int i = 0; i <= d; ++i) {
                sum += a[i] * pow(check, i);
            }

            ans[(check+1) % (d+3)] = abs(sum - v[check]);
        }

        cout << distance(ans.begin(), min_element(ans.begin(), ans.end())) << endl;
    }

    return 0;
}



Measured memory_bytes: 3228