为什么会MLE

#include<iostream>
#include<cmath>
//#define int long long
using namespace std;
int ans;
int gcd(int a,int b){
	if(a<b) swap(a,b);
	if(a%b==0) return b;
	return gcd(b,a%b);
}
signed main(){
	int n,m;
	std::ios::sync_with_stdio(false);
	std::cin.tie(0);
	cin>>n>>m;
	ans=m;
	for(int i=2;i<=n;i++){
		cin>>m;
		if(m<0) m=-m; 
		else if (m==0) continue;
		ans=gcd(ans,m);
	}
	cout<<ans;
	return 0;
}