A_Guess_the_Maximum.cpp

#include<bits/stdc++.h>

#define ll long long
#define forn(i, n) for(int i = 0; i < n; i++)
#define for1(i, n) for(int i = 1; i <= n; i++)
#define foru(i, n) for(int i = n-1; i >= 0; i--)
#define fi first
#define se second
#define all(x) (x).begin(),(x).end()
#define allp(x) (x).begin(), (x).begin() + (x).size()/2, (x).rbegin()
#define pb push_back
#define out(ans) cout<<ans<<endl
#define yn(a) cout<< (a ? "YES": "NO") <<endl

using namespace std;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef double dl;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    int t;
    cin >> t;
    while (t--) {
        int n; 
        cin >> n;

        vi v(n);
        forn(i, n) cin >> v[i];

        int mini = INT_MAX;

        for (int i = 0; i < n - 1; i++) {
            mini = min(mini, max(v[i], v[i + 1]));
        }

        cout << mini - 1 << endl;
    }
    return 0;
}