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

int main() {
	int a[100005];
	int n, b;
	cin >> n >> b;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];

	}
	for (int j = 1; j <= n; j++) {
		b = b - a[j];
		if (b <= 0) {
			cout << j;
			break;
		}
	}
	if (b > 0) {
		cout << "-1";
	}

	return 0;
}

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

int main() { int a[100005]; int n, b; cin >> n >> b; for (int i = 1; i <= n; i++) { cin >> a[i];

}
for (int j = 1; j <= n; j++) {
	b = b - a[j];
	if (b <= 0) {
		cout << j;
		break;
	}
}
if (b > 0) {
	cout << "-1";
}

return 0;

}