#include <stdio.h>

const long long inf = -(1LL << 60);

void chmax(long long *a, long long b)
{
	if (*a < b) *a = b;
}

int main()
{
	int i, N, A[5001][3];
	scanf("%d", &N);
	for (i = 1; i <= N; i++) scanf("%d %d %d", &(A[i][0]), &(A[i][1]), &(A[i][2]));
	
	int j, k, jj, kk, cur, prev;
	long long dp[2][3][5003], tmp, tmpp;
	for (j = 0; j < 3; j++) {
		for (k = 0; k <= N; k++) {
			dp[0][j][k] = inf;
			dp[1][j][k] = inf;
		}
	}
	for (i = 1, cur = 1, prev = 0, dp[0][0][0] = 0, dp[0][1][0] = 0, dp[0][2][0] = 0; i <= N; i++, cur ^= 1, prev ^= 1) {
		for (j = 0; j < 3; j++) {
			for (k = 0; k < N; k++) {
				tmp = dp[prev][j][k];
				dp[prev][j][k] = inf;
				
				for (jj = 0; jj < 3; jj++) {
					if (jj == j) continue;
					kk = k + A[i][jj];
					if (kk >= N) chmax(&(dp[cur][jj][N]), tmp + (long long)(kk + kk - (N - i)) * (N - i + 1) / 2);
					else if (kk > 0) chmax(&(dp[cur][jj][kk-1]), tmp + kk);
					else chmax(&(dp[cur][jj][kk]), tmp);
				}
			}
			tmp = dp[prev][j][N];
			dp[prev][j][N] = inf;
			for (jj = 0; jj < 3; jj++) {
				if (jj != j) {
					for (k = i, tmpp = tmp; k <= N; k++) {
						if (A[i][jj] - (k - i) > 0) tmpp += A[i][jj] - (k - i);
						else break;
					}
					chmax(&(dp[cur][jj][N]), tmpp);
				}
			}
		}
	}
	
	long long ans = 0;
	for (j = 0; j < 3; j++) for (k = 0; k <= N; k++) chmax(&ans, dp[prev][j][k]);
	printf("%lld\n", ans);
	fflush(stdout);
	return 0;
}