//C++
#include <iostream>
#include <vector>
using namespace std;
int main(){
    vector<long long> ai;
    vector<long long> test;
    int a,b;
    cin >> a;
    for(int i = 0;i < a;i++){
        cin >> b;
        ai.push_back(b);
    }
    for(int i = 1;i < a;i++){
        test.clear();
        for(int j = 0;j < ai.size() - 1;j++){
            test.push_back(ai[j] * ai[j + 1]);
        }
        ai.assign(test.begin(),test.end());//see STL
    }
    cout << ai[0];
    return 0;
}

帮我看看哪里错了，时间超限+答案错误+被取消😕