496A

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cerr.tie(NULL);
	int n,i;
	s1(n);
	int x;
	int stairways = 0;
	int currStairs = 0;
	VLL res;
	For1(i,0,n){
		s1(x);
		currStairs++;
		if(x==1 && stairways==0){
			stairways++;
		}else if(x==1){
			stairways++;
			res.pb(currStairs-1);
			currStairs = 1;
		}
	}
	res.pb(currStairs);
	pf(stairways)<<"\n";
	pfArr(res);
	return 0;
}