MATCH

#include <bits/stdc++.h>
using namespace std;
#define PB push_back
#define ZERO (1e-10)
#define INF (1<<29)
#define CL(A,I) (memset(A,I,sizeof(A)))
#define DEB printf("DEB!\n");
#define D(X) cout<<"  "<<#X": "<<X<<endl;
#define EQ(A,B) (A+ZERO>B&&A-ZERO<B)
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
#define IN(n) int n;scanf("%d",&n);
#define FOR(i, m, n) for (int i(m); i < n; i++)
#define REP(i, n) FOR(i, 0, n)
#define F(n) REP(i, n)
#define FF(n) REP(j, n)
#define FT(m, n) FOR(k, m, n)
#define aa first
#define bb second
void ga(int N,int *A){F(N)scanf("%d",A+i);}
#define MX (1<<20)
ll gcd(ll a,ll b,ll&s,ll&t){
    if(!b)return t=0,s=a<0?-1:1,a<0?-a:a;
    ll g=gcd(b,a%b,t,s);t-=a/b*s;return g;
}
ll inv(ll n,ll m){ll s,t;return gcd(n,m,s,t),s>0?s:s+m;}
const ll RW=1<<25,m=5*RW+1,R=243,R1=114609789;
void fft(ll*a,int n,bool I){
    int J=0;
    FT(1,n){
        int b=n>>1;
        while(J>=b)J-=b,b>>=1;
        J+=b;
        if(k<J)swap(a[k],a[J]);
    }
    for(int k=2;k<=n;k<<=1) {
        ll W=I?R1:R;
        for(ll i=k;i<RW;i<<=1)W*=W,W%=m;
        for(int i=0;i<n;i+=k) {
            ll w=1;
            FF(k/2){
                ll u=a[i+j],v=a[i+j+k/2]*w%m;
                a[i+j]=u+v<m?u+v:u+v-m;
                a[i+j+k/2]=u-v>=0?u-v:u-v+m;
                w*=W,w%=m;
            }
        }
    }
    ll r=inv(n,m);
    if(I)F(n)a[i]=a[i]*1ll*r%m;
}
int fftV(ll*A,int S,ll*B,int R,ll*C){
    int L=1;
    while(L<=S<<1||L<=R<<1)L<<=1;
    fft(A,L,0),fft(B,L,0);
    F(L)C[i]=A[i]*B[i]%m;
    return fft(C,L,1),L;
}
ll P[4][MX],p[4][MX],O[4][MX],S[MX];
char s[MX],r[MX];
int L,Q,l;
#define MP(C) (C==65?0:C==67?1:C=='G'?2:3)
int main(void){
    scanf("%s%s",s,r),L=strlen(s),l=strlen(r);
    F(L)P[MP(s[i])][i]=1;
    F(l)p[MP(r[i])][l-i-1]=1;
    F(4)fftV(P[i],L,p[i],l,O[i]);
    F(4)FF(L)S[j]+=O[i][j];
    printf("%lld\n",l-*max_element(S+l-1,S+L));
    return 0;
}