poj 2088

#include <iostream>
#include <cstdio>
#include <iomanip>
#include <string>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <set>
#include <vector>
#include <map>
#include <algorithm>
#include <cmath>
#include <stack>

#define INF 0x3f3f3f3f
#define LINF 0x3f3f3f3f3f3f3f3f
#define ll long long
#define ull unsigned long long
#define uint unsigned int

using namespace std;

int g[22][22], cost[22];
int dp[(1 << 20) + 10];
int n, ans;

void floyd() {
	for (int k = 0; k < n; k++) {
		for (int i = 0; i < n; i++) {
			if (i == k)continue;
			for (int j = 0; j < n; j++) {
				if (j == k || i == j)continue;
				g[i][j] = min(g[i][j], g[i][k] + g[k][j]);
			}
		}
	}
}

void dfs(int last, int count, int now) {
	if (ans == n)return;
	if (ans < count)ans = count;
	if (dp[now] <= 0)return;

	for (int i = 0; i < n; i++) {
		if (!(now&(1 << i)) && dp[now] - g[last][i] - cost[i] >= 0) {
			if (dp[now | (1 << i)] < dp[now] - g[last][i] - cost[i]){
				dp[now | (1 << i)] = dp[now] - g[last][i] - cost[i];
				dfs(i, count + 1, now | (1 << i));
			}
		}
	}
}

int main() {
	while (scanf("%d", &n) && n) {
		for (int i = 0; i < n; ++i)
			scanf("%d", cost + i);

		for (int i = 0; i < n; ++i)
			for (int j = 0; j < n; ++j)
				scanf("%d", &g[i][j]);

		floyd();
		memset(dp, -1, sizeof(dp));
		ans = 0;
		for (int i = 0; i < n; ++i)
			if (cost[i] <= 420) {
				dp[1 << i] = 420 - cost[i];
				dfs(i, 1, 1 << i);
			}

		printf("%d\n", ans);
	}
	return 0;
}