bugs program received signal sigsegv, segmentation fault

Question

When I try to run this program, it doesn't work. When I go to debugs, a message pops up "program received signal sigsegv, segmentation fault";

# include <bits/stdc++.h>
using namespace std;

int main() {
    
int a[1000000]; 
cout<< a[2];
return 0;
}