#include <bits/stdc++.h>

using namespace std;
#define FOR(i,n) for(int i = 0; i < (n); i++)
#define sz(c) ((int)c.size())
#define ten(n) ((int)1e##n)
using ll = long long;
using Pii = pair<int, int>;
using Pll = pair<ll, ll>;

template<typename ...> static inline int getchar_unlocked(void) { return getchar(); }
template<typename ...> static inline void putchar_unlocked(int c) { putchar(c); }
#define mygc(c) (c)=getchar_unlocked()
#define mypc(c) putchar_unlocked(c)
void reader(int& x) { int k, m = 0; x = 0; for (;;) { mygc(k); if (k == '-') { m = 1; break; }if ('0' <= k&&k <= '9') { x = k - '0'; break; } }for (;;) { mygc(k); if (k<'0' || k>'9')break; x = x * 10 + k - '0'; }if (m) x = -x; }
void reader(ll& x) { int k, m = 0; x = 0; for (;;) { mygc(k); if (k == '-') { m = 1; break; }if ('0' <= k&&k <= '9') { x = k - '0'; break; } }for (;;) { mygc(k); if (k<'0' || k>'9')break; x = x * 10 + k - '0'; }if (m) x = -x; }
int reader(char c[]) { int i, s = 0; for (;;) { mygc(i); if (i != ' '&&i != '\n'&&i != '\r'&&i != '\t'&&i != EOF) break; }c[s++] = i; for (;;) { mygc(i); if (i == ' ' || i == '\n' || i == '\r' || i == '\t' || i == EOF) break; c[s++] = i; }c[s] = '\0'; return s; }
int reader(string& c) { int i; for (;;) { mygc(i); if (i != ' '&&i != '\n'&&i != '\r'&&i != '\t'&&i != EOF) break; }c.push_back(i); for (;;) { mygc(i); if (i == ' ' || i == '\n' || i == '\r' || i == '\t' || i == EOF) break; c.push_back(i); }; return sz(c); }
template <class T, class S> void reader(T& x, S& y) { reader(x); reader(y); }
template <class T, class S, class U> void reader(T& x, S& y, U& z) { reader(x); reader(y); reader(z); }
template <class T, class S, class U, class V> void reader(T& x, S& y, U& z, V & w) { reader(x); reader(y); reader(z); reader(w); }
void writer(int x, char c) { int s = 0, m = 0; char f[10]; if (x<0)m = 1, x = -x; while (x)f[s++] = x % 10, x /= 10; if (!s)f[s++] = 0; if (m)mypc('-'); while (s--)mypc(f[s] + '0'); mypc(c); }
void writer(ll x, char c) { int s = 0, m = 0; char f[20]; if (x<0)m = 1, x = -x; while (x)f[s++] = x % 10, x /= 10; if (!s)f[s++] = 0; if (m)mypc('-'); while (s--)mypc(f[s] + '0'); mypc(c); }
void writer(const char c[]) { int i; for (i = 0; c[i] != '\0'; i++)mypc(c[i]); }
void writer(const string& x, char c) { int i; for (i = 0; x[i] != '\0'; i++)mypc(x[i]); mypc(c); }
void writer(const char x[], char c) { int i; for (i = 0; x[i] != '\0'; i++)mypc(x[i]); mypc(c); }
template<class T> void writerLn(T x) { writer(x, '\n'); }
template<class T, class S> void writerLn(T x, S y) { writer(x, ' '); writer(y, '\n'); }
template<class T, class S, class U> void writerLn(T x, S y, U z) { writer(x, ' '); writer(y, ' '); writer(z, '\n'); }
template<class T> void writerArr(T x[], int n) { if (!n) { mypc('\n'); return; }FOR(i, n - 1)writer(x[i], ' '); writer(x[n - 1], '\n'); }
template<class T> void writerArr(vector<T>& x) { writerArr(x.data(), (int)x.size()); }

template<class T> void chmin(T& a, const T& b) { if (a > b) a = b; }
template<class T> void chmax(T& a, const T& b) { if (a < b) a = b; }

template<class T> T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }
template<class T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
ll mod_pow(ll a, ll n, ll mod) {
	ll ret = 1;
	ll p = a % mod;
	while (n) {
		if (n & 1) ret = ret * p % mod;
		p = p * p % mod;
		n >>= 1;
	}
	return ret;
}
template<class T> T extgcd(T a, T b, T& x, T& y) { for (T u = y = 1, v = x = 0; a;) { T q = b / a; swap(x -= q * u, u); swap(y -= q * v, v); swap(b -= q * a, a); } return b; }
template<class T> T mod_inv(T a, T m) { T x, y; extgcd(a, m, x, y); return (m + x % m) % m; }

int l[2000], r[2000];

int main() {
	string a, b; reader(a, b);
	{
		bool t = false;
		for (auto& x : b) if (x == '1') t = true;
		if (!t) {
			if (a == b) {
				puts("0");
			} else {
				puts("-1");
			}
			return 0;
		}
	}

	FOR(i, sz(a)) {
		int idx = 0;
		while (true) {
			int ni = (i - idx + sz(a)) % sz(a);
			if (b[ni] == '1') {
				break;
			}
			idx++;
		}
		l[i] = idx;
	}
	FOR(i, sz(a)) {
		int idx = 0;
		while (true) {
			int ni = (i + idx) % sz(a);
			if (b[ni] == '1') {
				break;
			}
			idx++;
		}
		r[i] = idx;
	}

	static int rfix[4010];
	int ans = ten(6);
	FOR(rshift, sz(a)) {
		vector<Pii> vp;
		FOR(i, sz(a)) {
			if (a[i] != b[(i + rshift) % sz(a)]) {
				vp.emplace_back(l[i], r[i]);
			}
		}

		{
			sort(vp.begin(), vp.end());
			int mx = 0;
			int vpi = sz(vp) - 1;
			for (int x = sz(a); x >= 0; x--) {
				rfix[x] = mx;
				while (vpi >= 0 && vp[vpi].first == x) {
					mx = max(mx, vp[vpi].second);
					vpi--;
				}
			}
		}

		FOR(x, 2) {
			int lstart = -1, rstart;
			FOR(lm, sz(a)) {
				int rm = rshift + lm;
				if (x) rm -= sz(a);
				if (rm < 0) continue;

				//printf("  %d %d\n", lm, rm);
				lstart = lm;
				rstart = rm;
				break;
			}
			if (lstart == -1) {
				continue;
			}

			int additional = ten(5);
			for (int ladd = 0; lstart + ladd <= sz(a) + 10; ladd++) {
				int radd = rfix[lstart + ladd] - rstart;
				radd = max(radd, 0);
				additional = min(additional, ladd + radd);
			}

			int cans = sz(vp) + additional * 2 + lstart + rstart;
			//printf("%d %d %d\n",lstart, rstart, cans);
			ans = min(ans, cans);
		}
	}

	writerLn(ans);

	return 0;
}

Measured memory_bytes: 256