import java.util.*;

public class Neighbor_joining {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int size = sc.nextInt();
        String names[] = new String[size];
        int values[][][] = new int[size][size][size];
        int sum[][] = new int[size][size];
        for (int i = 0; i < size; i++) {
            names[i] = sc.next();
            for (int j = 0; j < size; j++) {
                values[0][i][j] = sc.nextInt();
                sum[0][i] += values[0][i][j];
            }
        }
        int njvalues[][] = new int[size][size];
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                if (i == j) {
                    njvalues[i][j] = 0;
                } else {
                    njvalues[i][j] = (size - 2) * values[0][i][j] - sum[0][i] - sum[0][j];
                }
            }
        }
        boolean x = true;
        int min = 999999999;
        int minvalues[] = new int[2];
        float limblength[] = new float[size];
        Map<String, Float> output = new HashMap<String, Float>();
        int iteration = 0;
        while (iteration != size) {
            for (int i = 0; i < size - iteration; i++) {
                for (int j = 0; j < size - iteration; j++) {
                    if (njvalues[i][j] < min && i != j) {
                        min = njvalues[i][j];
                        minvalues[0] = i;
                        minvalues[1] = j;
                    }
                }
            }
            float delta = 0;
            if (size - iteration - 2 > 0) {
                delta = (sum[iteration][minvalues[0]] - sum[iteration][minvalues[1]]) / (size - iteration - 2);
            } else {
                delta = sum[iteration][minvalues[0]] - sum[iteration][minvalues[1]];
            }
            limblength[minvalues[0]] = (values[iteration][minvalues[0]][minvalues[1]] + delta) / 2;
            limblength[minvalues[1]] = (values[iteration][minvalues[0]][minvalues[1]] - delta) / 2;
            if (!output.keySet().contains(names[minvalues[0]])) {
                output.put(names[minvalues[0]], limblength[minvalues[0]]);
            }
            if (!output.keySet().contains(names[minvalues[1]])) {
                output.put(names[minvalues[1]], limblength[minvalues[1]]);
            }
            iteration++;
            for (int i = 0; i < (size - iteration); i++) {
                for (int j = 0; j < (size - iteration); j++) {
                    if (i == minvalues[1] || j == minvalues[1]) {
                        values[iteration][i][j] = 0;
                    } else if (i != j) {
                        if (i == minvalues[0]) {
                            values[iteration][i][j] = values[iteration - 1][minvalues[0]][j] + values[iteration - 1][minvalues[1]][j] - values[iteration - 1][minvalues[0]][minvalues[1]];
                        } else if (j == minvalues[0]) {
                            values[iteration][i][j] = values[iteration - 1][i][minvalues[0]] + values[iteration - 1][i][minvalues[1]] - values[iteration - 1][minvalues[0]][minvalues[1]];
                        }
                    }
                    sum[iteration][i] += values[iteration][i][j];
                }
            }

            for (int i = 0; i < size - iteration; i++) {
                for (int j = 0; j < size - iteration; j++) {
                    if (values[iteration][i][j] == 0) {
                        njvalues[i][j] = 0;
                    } else {
                        njvalues[i][j] = (size - iteration - 2) * values[iteration][i][j] - sum[iteration][i] - sum[iteration][j];
                    }
                }
            }
            min = 999999999;
        }
        for (Map.Entry m : output.entrySet()) {
            System.out.println(m.getKey() + " " + m.getValue());
        }
    }
}