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// Wojciech Sidor
// #define DBG
#include <cstdio>
#include <cstring>
#include <string>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <cstdlib>
#include <cassert>
#include <cmath>
#include <cstdarg>
using namespace std;
#define PB push_back
#define IT iterator
#define MP make_pair
#define F first
#define S second
#define X first
#define Y second
#define NL printf("\n")
#define SZ(v) ((int)(v).size())
#define ALL(x) (x).begin(), (x).end()
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define FORE(i,a,b) for(int i=(a);i<=(b);++i)
#define FORD(i,a,b) for(int i=(a);i>=(b);--i)
#define FORC(i,a) for(__typeof((a).begin()) i = (a).begin(); i != (a).end(); ++i)
#define W(x) do { if (DBG) printf("%s:%d %s = %d\n", __LINE__, __func__, #x, x); } while (0)

typedef long double LD;
typedef double DL;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<LD,LD> PLD;
typedef pair<int,int> PII;
typedef pair<LL,LL> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<PII> VPII;
void memcheck()
{
#ifdef DBG
    char c[100];
    FILE *p = fopen("/proc/self/status","r");
    while (fgets(c,100,p) )
        if (strncmp("VmPeak",c,6)==0)
            fputs(c, stderr);
    fclose(p);
#endif
}
//------ /headers --------

void __printf__(const char *s, ...)
{
#ifdef DBG
    va_list vl;
    va_start(vl, s);
    vfprintf(stderr, s, vl);
#endif
}

#define debprint(format, ...) do { __printf__("[%s:%d] " format "\n", __func__, __LINE__, __VA_ARGS__); } while (0);

const int MAXN = 2003;
int input[MAXN][MAXN];
int mins_up[MAXN][MAXN];
int mins_right[MAXN][MAXN];
ULL result[MAXN][MAXN];
int size;

void read_input() {
    scanf("%d", &size);
    for (int i = 0; i < size; ++i) {
        for (int j = i; j < size; ++j) {
            scanf("%d", &input[i][j]);
            mins_up[i][j] = input[i][j];
            mins_right[i][j] = input[i][j];
            result[i][j] = input[i][j];
        }
    }
}

void preprocess() {
    for (int i = 0; i < size; ++i) {
        for (int j = i - 1; j >= 0; --j) {
            mins_up[j][i] = min(mins_up[j + 1][i], input[j][i]);
        }
    }

    for (int i = 0; i < size; ++i) {
        for (int j = i + 1; j < size; ++j) {
            mins_right[i][j] = min(mins_right[i][j - 1], input[i][j]);
        }
    }
}

ULL get_result(int i, int j) {
    if (i > j) {
        return 0;
    }
    return result[i][j];
}

int get_min(int begin, int end, int middle) {
    int mn = 1000000010;
    for (int i = begin; i <= middle; ++i) {
        for (int j = middle; j <= end; ++j) {
            mn = min(mn, input[i][j]);
        }
    }
    return mn;
}

void compute() {
    for (int len = 2; len <= size; ++len) {
        for (int begin = 0; begin <= size - len; ++begin) {
            ULL min_tmp = -1;
            int end = begin + len - 1;
            for (int middle = begin; middle <= end; ++middle) {
                debprint("[%d-%d-%d] bef: %llu middle: %d aft: %llu",
                        begin, middle, len, get_result(begin, middle - 1),
                        get_min(begin, end, middle),
                        get_result(middle + 1, end));
                min_tmp = min(
                    min_tmp,
                    get_result(begin, middle - 1)
                        + get_min(begin, end, middle)
                        + get_result(middle + 1, end));
            }
            result[begin][end] = min_tmp;
            debprint("result[%d][%d] = %llu", begin, end, result[begin][end]);
        }
    }
}

int main() {
    read_input();
    preprocess();
    compute();
    printf("%llu\n", result[0][size - 1]);
}