#include<bits/stdc++.h>
using namespace std;
#define X first
#define Y second
#define mp make_pair
#define pb push_back
#define rep(i,a,n) for(int i=(a);i<=(n);++i)
#define dep(i,a,n) for(int i=(a);i>=(n);--i)
#define eps 1e-8
#define pi 3.1415926535897
#define sqr(x) ((x)*(x))
#define MAX(a,b) a=max(a,b)
#define MIN(a,b) a=min(a,b)
#define SZ(x) ((int)(x).size())
#define CPY(a,b) memcpy(a,b,sizeof(a))
#define CLR(a) memset(a,0,sizeof(a))
#define POSIN(x,y) (1<=(x)&&(x)<=n&&1<=(y)&&(y)<=m)
#define all(x) (x).begin(),(x).end()
#define COUT(S,x) cout<<fixed<<setprecision(x)<<S<<endl
#define buli(x) (__builtin_popcountll(x))
#define bur0(x) (__builtin_ctzll(x))
#define bul2(x) (63-__builtin_clzll(x))
#define pw(x) ((ll(1))<<(x))
#define upmo(a,b) (((a)=((a)+(b))%mo)<0?(a)+=mo:(a))
#define mmo(a,b) (((a)=1ll*(a)*(b)%mo)<0?(a)+=mo:(a))
#define y0 y0z
#define y1 y1z
#define yn ynz
#define j0 j0z
#define j1 j1z
#define jn jnz
#define tm tmz
#ifdef LOCAL
#define debug(...) fprintf(stderr, __VA_ARGS__)
#else
#define debug(...) 
#endif
typedef long long ll;
typedef double lf;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<lf,lf> pff;
typedef complex<double> CD;
const int inf=0x3f3f3f3f;
const int mo=1000000007;
inline void gn(long long&x){
	int sg=1;char c;while(((c=getchar())<'0'||c>'9')&&c!='-');c=='-'?(sg=-1,x=0):(x=c-'0');
	while((c=getchar())>='0'&&c<='9')x=x*10+c-'0';x*=sg;
}
inline void gn(int&x){long long t;gn(t);x=t;}
inline void gn(unsigned long long&x){long long t;gn(t);x=t;}
inline void gn(double&x){double t;scanf("%lf",&t);x=t;}
inline void gn(long double&x){double t;scanf("%lf",&t);x=t;}
template<class T1,class T2>inline void gn(T1&r,T2&s){gn(r),gn(s);}
template<class T1,class T2,class T3>inline void gn(T1&r,T2&s,T3&t){gn(r),gn(s),gn(t);}
template<class T1,class T2,class T3,class T4>inline void gn(T1&r,T2&s,T3&t,T4&u){gn(r),gn(s),gn(t),gn(u);}
inline void gs(char *s){scanf("%s",s);}
inline void gc(char &c){while((c=getchar())>126 || c<33);}
inline void pc(char c){putchar(c);}
const int DX[]={1,0,-1,0},DY[]={0,1,0,-1};
ll powmod(ll a,ll b) {ll res=1;a%=mo;for(;b;b>>=1){if(b&1)res=res*a%mo;a=a*a%mo;}return res;}
ll powmod(ll a,ll b,ll mo) {ll res=1;a%=mo;for(;b;b>>=1){if(b&1)res=res*a%mo;a=a*a%mo;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
//*******************************************

const int N=111111,M=111111;
int l,m,n,t,C;
char s1[N],s2[N];
int a[N],b[N],c[N];
int ans;
void work(){
	rep(p,0,n-1){
		int cnt=0;
		rep(i,1,n)if(a[i]!=b[i+p])++cnt;
		int pre=n;while(!b[pre])--pre;
		int nxt=p+2;while(!b[nxt])++nxt;
		int sum=0;
		rep(i,1,1+p)sum+=b[i];
		vector<pii>V;
		rep(i,1,n){
			//printf("%d %d %d %d\n",i,pre,nxt,sum);
			if(a[i]!=b[i+p]&&sum==0){
				V.pb(mp(i-pre+n,nxt-(i+p)));
			}
			sum+=b[i+p+1]-b[i];
			if(b[i])pre=i+n;
			if(nxt==i+p+1){++nxt;while(!b[nxt])++nxt;}
		}
		V.pb(mp(0,0));
		sort(V.begin(),V.end());
		//printf("%d %d\n",p,ans);
		//for(auto i:V)printf("%d %d\n",i.X,i.Y);puts("");
		c[SZ(V)]=0;
		dep(i,SZ(V)-1,0)c[i]=max(c[i+1],V[i].Y);
		rep(i,0,SZ(V)-1)MIN(ans,cnt+p+2*(V[i].X+c[i+1]));
	}
}
int main(){
#ifdef LOCAL
	freopen("D.in","r",stdin);//freopen("D.out","w",stdout);
#endif
	scanf("%s%s",s1+1,s2+1);n=strlen(s1+1);
	rep(i,1,n)a[i]=s1[i]-'0',b[i]=s2[i]-'0';
	rep(i,n+1,n+n)a[i]=a[i-n],b[i]=b[i-n];
	int sum1=0,sum2=0;
	rep(i,1,n)sum1+=s1[i]-'0',sum2+=s2[i]-'0';
	if(sum2==0&&sum1){puts("-1");return 0;}
	ans=inf;
	work();
	rep(i,1,n/2)swap(a[i],a[n-i+1]),swap(b[i],b[n-i+1]);
	rep(i,n+1,n+n)a[i]=a[i-n],b[i]=b[i-n];
	work();
	printf("%d\n",ans);
	return 0;
}


Measured memory_bytes: 384