rt，调了半小时感觉没什么问题，wa test10

贪心做的

ll T,n,a[maxn],ans;
ll sum[maxn];
map<ll,int>mp;

inline ll read(void)
{
	ll num,sign=1;char c;
	while(!isdigit(c=getchar()))if(c=='-')sign=0;num=c-'0';
	while(isdigit(c=getchar()))num=(num<<1)+(num<<3)+c-'0';
	return sign?num:-num;
}

signed main(void)
{
	n=read();
	for(register int t,ls=0,i=1;i<=n;++i)
	{
		a[i]=read();
		sum[i]=sum[i-1]+a[i];
		if(!sum[i])ls=i-1,++ans;
		else if((t=mp[sum[i]])&&t>=ls)ls=i-1,++ans;
		mp[sum[i]]=i;
	}
	cout<<ans<<endl;
}