#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;
using vpii = vector<pii>;
#define repn(i, n) for (int i = 1; i <= (int)n; i++)
#define rep(i, n) for (int i = 0; i < (int)n; i++)
#define repr(i, m, n) for (int i = (int)m; i <= (int)n; i++)
#define repd(i, m, n) for (int i = (int)m; i >= (int)n; i--)
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#ifdef LILYWHITE
#define eprintf(...) fprintf(stderr, __VA_ARGS__)
#else
#define eprintf(...) ;
#endif
const int __attribute__((unused)) INF = 0x3f3f3f3f;
template <typename T> inline T rd(T &x) {
    x = 0;
    T neg = 1;
    char c = 0;
    while (c < '0' || c > '9') {
        if (c == '-')
            neg = -1;
        c = getchar();
    }
    while (c >= '0' && c <= '9') {
        x = x * 10 + c - 48;
        c = getchar();
    }
    x *= neg;
    return x;
}
template <typename T, typename... Args> inline void rd(T &x, Args &...args) {
    rd(x);
    rd(args...);
}
#define MULTI
const int N = 1000100;
ll a[N], dp[N][2];
void Main() {
    int n;
    rd(n);
    repn(i, n) {
        dp[i][0] = dp[i][1] = 0;
    }
    repn(i, n) {
        rd(a[i]);
    }
    for (int i = 1; i <= n; i++) {
        dp[i][0] = max(dp[i - 1][1] + a[i], a[i]);
        if (i > 1) dp[i][1] = dp[i - 1][0] + a[i];
    }
//    repn(i, n) cerr << dp[i][0] << ' ' << dp[i][1] << endl;
    ll ans = -1e16;
    repn(i, n) chmax(ans, dp[i][0]);
    cout << ans << endl;
}
int main() {
#ifdef MULTI
    int T;
    rd(T);
    while (T--)
#endif
        Main();
    return 0;
}