import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;
import java.lang.Math;

class point {
    int index=-2;
    point parent;
    int distance;
    int distance_to;
    int cap;
    ArrayList<point> list = new ArrayList<point>();
}

class PriorityQueue{
    int count;
    point[] heap;
    PriorityQueue(int n){
        int i;
        this.heap = new point[n];
        for(i = 0; i < n; i++){
            this.heap[i] = new point();
        }
        this.count = 0;
    }
    public void insert(point u){
        int i = this.count++;
        point temp;
        this.heap[i] = u;
        while (i > 0 && this.heap[(i-1)/2].distance > this.heap[i].distance){
            temp = this.heap[(i-1)/2];
            this.heap[(i-1)/2] = this.heap[i];
            this.heap[i] = temp;
            this.heap[i].index=i;
            i = (i-1)/2;
        }
        this.heap[i].index=i;
    }
    public point ExtractMin(){
        point temp;
        temp = this.heap[0];
        this.count--;
        if(this.count > 0){
            this.heap[0] = this.heap[this.count];
            this.heap[0].index=0;
            heapify(this.heap, 0);
        }
        return temp;
    }
    public void heapify(point[] heap, int i){
        int l, r, j;
        point temp;
        for(;;){
            l = 2*i+1;
            r = l+1;
            j = i;
            if(l < this.count && (heap[l].distance < heap[j].distance)) j = l;
            if(r < this.count && (heap[r].distance < heap[j].distance)) j = r;
            if(i == j) break;
            temp = heap[i];
            heap[i] = heap[j];
            heap[j] = temp;
            this.heap[i].index=i;
            this.heap[j].index=j;
            i = j;
        }
    }
    public void increaseKey(point x, int y){
        int i = x.index;
        point temp;
        x.distance=y;
        while(i > 0 && this.heap[(i-1)/2].distance > y){
            temp = this.heap[(i-1)/2];
            this.heap[(i-1)/2] = this.heap[i];
            this.heap[i] = temp;
            this.heap[i].index=i;
            i = (i-1)/2;
        }
        x.index=i;
    }
}


public class MapRoute {
    public static void main(String[] arg) {
        Scanner sc = new Scanner(System.in);
        int i=0,j=0,n=sc.nextInt(),distance=0,k=0;
        point [][] graph=new point[n][n];
        int[][] matrix=new int[n][n];
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                matrix[i][j]=sc.nextInt();
                graph[i][j]=new point();
            }
        }
        for(i=0;i<n;i++) {
            for (j = 0; j < n; j++) {
                graph[i][j].parent = null;
                graph[i][j].distance = 1000000000;
                graph[i][j].distance_to = matrix[i][j];
                if (i > 0) {
                    graph[i][j].list.add(graph[i - 1][j]);
                    graph[i][j].cap++;
                }
                if (i < n - 1) {
                    graph[i][j].list.add(graph[i + 1][j]);
                    graph[i][j].cap++;
                }
                if (j > 0) {
                    graph[i][j].list.add(graph[i][j - 1]);
                    graph[i][j].cap++;
                }
                if (j < n - 1) {
                    graph[i][j].list.add(graph[i][j + 1]);
                    graph[i][j].cap++;
                }
            }
        }
        PriorityQueue q = new PriorityQueue(n*n);
        graph[0][0].distance=graph[0][0].distance_to;
        q.insert(graph[0][0]);
        point v=new point();
        point u=new point();
        point answer=new point();
        while(q.count>0)
        {
            v=q.ExtractMin();
            if(v.equals(graph[n-1][n-1])) {
                answer = v;
                break;
            }
            for(i=0;i<v.cap;i++)
            {
                u=v.list.get(i);
                if(u!=v.parent) {
                    if (v.distance + u.distance_to < u.distance) {
                        u.distance = v.distance + u.distance_to;
                        u.parent = v;
                        q.insert(u);
                    }
                }
            }
        }
        System.out.println(answer.distance);
    }
}