#define _CRT_SECURE_NO_WARNINGS
#pragma target("avx")
#pragma optimize("O3")
#pragma optimize("unroll-loops")
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#define rep(i,n) for(int i=0;i<(lint)(n);i++)
#define REP(i,n) for(int i=1;i<=(lint)(n);i++)
#define all(V) V.begin(),V.end()
typedef long long lint;
typedef unsigned long long ulint;
typedef std::pair<lint, lint> P;
constexpr int INF = INT_MAX/2;
constexpr lint LINF = LLONG_MAX/2;
constexpr double eps = DBL_EPSILON;
constexpr double PI=3.141592653589793238462643383279;
template<class T>
class prique :public std::priority_queue<T, std::vector<T>, std::greater<T>> {};
template <class T, class U>
inline bool chmax(T& lhs, const U& rhs) {
	if (lhs < rhs) {
		lhs = rhs;
		return 1;
	}
	return 0;
}
template <class T, class U>
inline bool chmin(T& lhs, const U& rhs) {
	if (lhs > rhs) {
		lhs = rhs;
		return 1;
	}
	return 0;
}
inline lint gcd(lint a, lint b) {
	while (b) {
		lint c = a;
		a = b; b = c % b;
	}
	return a;
}
inline lint lcm(lint a, lint b) {
	return a / gcd(a, b) * b;
}
bool isprime(lint n) {
	if (n == 1)return false;
	for (int i = 2; i * i <= n; i++) {
		if (n % i == 0)return false;
	}
	return true;
}
template<typename T>
T mypow(T a, unsigned int b) {
	if (!b)return T(1);
	if (b & 1)return mypow(a, b - 1) * a;
	T memo = mypow(a, b >> 1);
	return memo * memo;
}
lint modpow(lint a, lint b, lint m) {
	if (!b)return 1;
	if (b & 1)return modpow(a, b - 1, m) * a % m;
	lint memo = modpow(a, b >> 1, m);
	return memo * memo % m;
}
template<typename T>
void printArray(std::vector<T>& vec) {
	rep(i, vec.size() - 1)std::cout << vec[i] << " ";
	std::cout << vec.back() << std::endl;
}
template<typename T>
void printArray(T l, T r) {
	T rprev = r;
	rprev--;
	for (T i = l; i != rprev; i++) {
		std::cout << *i << " ";
	}
	std::cout << *rprev << std::endl;
}
std::string a,b;
int c[2010],d[2010];
int main(){
	std::cin>>a>>b;
	int n=a.size();
	if(b==std::string(n,'0')){
		if(a!=std::string(n,'0'))std::cout<<-1<<std::endl;
		else std::cout<<0<<std::endl;
		return 0;
	}
	int now=-1;
	rep(i,n){
		if(b[i]=='1')now=i;
		if(now!=-1)c[i]=now;
	}
	rep(i,n){
		if(b[i]=='1')break;
		c[i]=now-n;
	}
	now=-1;
	for(int i=n-1;i>=0;i--){
		if(b[i]=='1')now=i;
		if(now!=-1)d[i]=now;
	}
	for(int i=n-1;i>=0;i--){
		if(b[i]=='1')break;
		d[i]=now+n;
	}
	int ans=INF;
	rep(i,n){
		std::vector<P> vec;
		rep(j,n){
			if(a[j]!=b[j])vec.emplace_back(j-c[j],d[j]-j);
		}
		if(vec.empty()){
			chmin(ans,i);
			continue;
		}
		std::sort(all(vec));
		std::vector<lint> max(vec.size());
		max.back()=vec.back().second;
		for(int j=vec.size()-2;j>=0;j--)max[j]=std::max(vec[j].second,max[j+1]);
		chmin(ans,vec.size()+max[0]+std::min(std::abs(-max[0]+i+n)%n,n-std::abs(-max[0]+i+n)%n));
		rep(j,(int)vec.size()-1){
			chmin(ans,vec.size()+vec[j].first*2+max[j+1]+std::min(std::abs(-max[j+1]+i+n)%n,n-std::abs(-max[j+1]+i+n)%n));
			chmin(ans,vec.size()+vec[j].first+max[j+1]*2+std::min(std::abs(vec[j].first+i+n)%n,n-std::abs(vec[j].first+i+n)%n));
		}
		chmin(ans,vec.size()+vec.back().first+std::min(std::abs(vec.back().first+i)%n,n-std::abs(vec.back().first+i)%n));
		b=b+b[0];
		b=b.substr(1,b.size()-1);
	}
	std::cout<<ans<<std::endl;
	return 0;
}


Measured memory_bytes: 384