#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>


struct Edge {
    uint32_t from;
    uint32_t to;
    uint32_t weight;

    Edge(uint32_t from, uint32_t to, uint32_t weight = 0) :
        from(from), to(to), weight(weight){}
};

bool operator<(const Edge& lhs, const Edge& rhs) {
    return lhs.weight < rhs.weight;
}

std::vector<Edge> GetMST(const std::vector<std::vector<Edge>>& graph) {
    const uint32_t INF = 101;
    const uint32_t verNum = graph.size();
    std::vector<uint32_t> distances(verNum, INF);
    std::vector<int64_t> predcessors(verNum, -1);
    std::vector<Edge> MST;
    std::priority_queue<std::pair<uint32_t, uint32_t>, std::vector<std::pair<uint32_t, uint32_t>>, std::greater<std::pair<uint32_t, uint32_t>>> queue;
    distances[0] = 0;
    //predcessors[0] = 0;
    queue.push({0, 0});
    while (!queue.empty()) {
        auto distAndVertex = queue.top();
        queue.pop();
        distances[distAndVertex.second] = 0;
        for (const auto& edge : graph[distAndVertex.second]) {
            if (distances[edge.to] > edge.weight) {
                distances[edge.to] = edge.weight;
                queue.push({edge.weight, edge.to});
                predcessors[edge.to] = distAndVertex.second;
            }
        }
    }
    for (uint32_t i = 0; i < verNum; ++i) {
        if (predcessors[i] != i) {
            MST.push_back(Edge(predcessors[i], i, distances[i]));
        }
    }
    return MST;
}


int main() {
    uint32_t verNum;
    std::cin >> verNum;
    std::vector<std::vector<Edge>> graph(verNum, std::vector<Edge>());
    uint32_t weight;
    for (uint32_t i = 0; i < verNum; ++i) {
        for (uint32_t j = 0; j < verNum; ++j) {
            std::cin >> weight;
            graph[i].push_back(Edge(i, j, weight));
        }
    }
    auto mst = GetMST(graph);
    uint32_t sum = 0;
    for (auto edge : mst) {
        //std::cout << edge.from << ' ' << edge.to << ' ' << edge.weight << '\n';
        sum += edge.weight;
    }
    std::cout << sum;

    //system("pause");
    return 0;
}