#include<bits/stdc++.h>
using namespace std;
#define MD 1000000007
struct modint{
  static unsigned md;
  unsigned val;
  modint(){
  }
  modint(int a){
    val = ord(a);
  }
  modint(unsigned a){
    val = ord(a);
  }
  modint(long long a){
    val = ord(a);
  }
  modint(unsigned long long a){
    val = ord(a);
  }
  void setmod(unsigned m){
    md = m;
  }
  unsigned ord(unsigned a){
    return a%md;
  }
  unsigned ord(int a){
    a %= md;
    if(a < 0){
      a += md;
    }
    return a;
  }
  unsigned ord(unsigned long long a){
    return a%md;
  }
  unsigned ord(long long a){
    a %= md;
    if(a < 0){
      a += md;
    }
    return a;
  }
  unsigned get(){
    return val;
  }
  modint &operator+=(modint a){
    val += a.val;
    if(val >= md){
      val -= md;
    }
    return *this;
  }
  modint &operator-=(modint a){
    if(val < a.val){
      val = val + md - a.val;
    }
    else{
      val -= a.val;
    }
    return *this;
  }
  modint &operator*=(modint a){
    val = ((unsigned long long)val*a.val)%md;
    return *this;
  }
  modint &operator/=(modint a){
    return *this *= a.inverse();
  }
  modint operator+(modint a){
    return modint(*this)+=a;
  }
  modint operator-(modint a){
    return modint(*this)-=a;
  }
  modint operator*(modint a){
    return modint(*this)*=a;
  }
  modint operator/(modint a){
    return modint(*this)/=a;
  }
  modint operator+(int a){
    return modint(*this)+=modint(a);
  }
  modint operator-(int a){
    return modint(*this)-=modint(a);
  }
  modint operator*(int a){
    return modint(*this)*=modint(a);
  }
  modint operator/(int a){
    return modint(*this)/=modint(a);
  }
  modint operator+(long long a){
    return modint(*this)+=modint(a);
  }
  modint operator-(long long a){
    return modint(*this)-=modint(a);
  }
  modint operator*(long long a){
    return modint(*this)*=modint(a);
  }
  modint operator/(long long a){
    return modint(*this)/=modint(a);
  }
  modint operator-(void){
    modint res;
    if(val){
      res.val=md-val;
    }
    else{
      res.val=0;
    }
    return res;
  }
  operator bool(void){
    return val!=0;
  }
  operator int(void){
    return get();
  }
  operator long long(void){
    return get();
  }
  modint inverse(){
    int a=val, b=md, t, u=1, v=0;
    modint res;
    while(b){
      t = a / b;
      a -= t * b;
      swap(a, b);
      u -= t * v;
      swap(u, v);
    }
    if(u < 0){
      u += md;
    }
    res.val = u;
    return res;
  }
  modint pw(unsigned long long b){
    modint a(*this), res;
    res.val = 1;
    while(b){
      if(b&1){
        res *= a;
      }
      b >>= 1;
      a *= a;
    }
    return res;
  }
  bool operator==(int a){
    return ord(a)==val;
  }
  bool operator!=(int a){
    return ord(a)!=val;
  }
}
;
modint operator+(int a, modint b){
  return modint(a)+=b;
}
modint operator-(int a, modint b){
  return modint(a)-=b;
}
modint operator*(int a, modint b){
  return modint(a)*=b;
}
modint operator/(int a, modint b){
  return modint(a)/=b;
}
modint operator+(long long a, modint b){
  return modint(a)+=b;
}
modint operator-(long long a, modint b){
  return modint(a)-=b;
}
modint operator*(long long a, modint b){
  return modint(a)*=b;
}
modint operator/(long long a, modint b){
  return modint(a)/=b;
}
inline void rd(int &x){
  int k, m=0;
  x=0;
  for(;;){
    k = getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
inline void wt_L(char a){
  putchar_unlocked(a);
}
inline void wt_L(int x){
  char f[10];
  int m=0, s=0;
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    putchar_unlocked('-');
  }
  while(s--){
    putchar_unlocked(f[s]+'0');
  }
}
inline void wt_L(modint x){
  int i;
  i = (int)x;
  wt_L(i);
}
unsigned modint::md;
int N;
int M;
int S[2000];
int T[2000];
modint *dp;
modint *nx;
modint dmem[4002];
int main(){
  int i, j, k;
  {
    modint x;
    x.setmod(MD);
  }
  rd(N);
  rd(M);
  {
    int Lj4PdHRW;
    for(Lj4PdHRW=0;Lj4PdHRW<N;Lj4PdHRW++){
      rd(S[Lj4PdHRW]);
    }
  }
  {
    int KL2GvlyY;
    for(KL2GvlyY=0;KL2GvlyY<M;KL2GvlyY++){
      rd(T[KL2GvlyY]);
    }
  }
  dp = dmem;
  nx = dmem + M + 1;
  for(j=0;j<M+1;j++){
    dp[j] = 1;
  }
  for(i=0;i<N;i++){
    nx[0] = 1;
    for(j=0;j<M;j++){
      if(S[i]!=T[j]){
        nx[j+1] = nx[j] + dp[j+1]- dp[j];
      }
      else{
        nx[j+1] = nx[j] + dp[j+1];
      }
    }
    swap(dp, nx);
  }
  wt_L(dp[M]);
  wt_L('\n');
  return 0;
}
// cLay varsion 20190626-1

// --- original code ---
// int N, M, S[2000], T[2000];
// modint *dp, *nx, dmem[4002];
// 
// {
//   int i, j, k;
//   rd(N,M,S(N),T(M));
// 
//   dp = dmem;
//   nx = dmem + M + 1;
// 
//   rep(j,M+1) dp[j] = 1;
//   rep(i,N){
//     nx[0] = 1;
//     rep(j,M) nx[j+1] = nx[j] + dp[j+1] if[S[i]!=T[j], - dp[j]];
//     swap(dp, nx);
//   }
//   wt(dp[M]);
// }


Measured memory_bytes: 256