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#include <cstdio>
#include <algorithm>

#define D(x)

using namespace std;
#define MAX 200100

typedef long long ll;
int a[MAX],t,n;

static int testX(ll A, ll x, ll sr, int yy) {
    ll B = sr - A - x;
    ll y = A*x*B;
    if (x >= 2) y += x*(x-1)*(A+B)/2;
    if (x >= 3) y += x*(x-1)*(x-2)/6;
    if (y >= yy) return true;
    return false;
}

static int findX(int from, int to, ll A, ll sr, int yy) {
    int x = -1;
    while(from <= to) {
        int ft2 = (from+to)/2;
        if (testX(A,ft2,sr,yy)) {
            x = ft2;
            to = ft2-1;
        } else {
            from = ft2 + 1;
        }
    }
    return x;
}

static bool test(ll sr) {
    ll A = 0;
    for(int i=0;i<n;i++) {
        ll to = min(200LL, sr - A);
        if (to < 0) return false;
        int x = findX(0,to, A, sr, a[i]);
//        printf("fx: %d to: %d\n", x, to);
        if (x < 0) return false;
        A+=x;
    }
    return true;
}

int main() {
    scanf("%d", &t);
    while(t--) {
        ll sa = 0, sr = 0;
        scanf("%d", &n);
        for(int i=0;i<n;i++) {
            scanf("%d", &a[i]);
            sa += a[i];
        }

        ll from = 0, to = 201008;
        while(from <= to) {
            int ft2 = (from+to)/2;
            if (test(ft2)) {
                sr = ft2;
                to = ft2-1;
            } else {
                from = ft2 + 1;
            }
        }
  
        printf("%lld\n",sr);
    }
}