#include<bits/stdc++.h>
#define F first
#define S second
#define MP make_pair
#define pb push_back
#define endl '\n'

using namespace std;

typedef long long LL;
typedef pair< int, int > P;
typedef pair< LL, LL > LP;
typedef pair< int, P > iP;
typedef pair< P, P > PP;

static const int INF = INT_MAX;
static const LL LINF = LLONG_MAX;
static const int MIN = INT_MIN;
static const LL LMIN = LLONG_MIN;
static const int MOD = 1000000007;
static const int SIZE = 100005;

int dx[] = {0, -1, 1, 0};
int dy[] = {-1, 0, 0, 1};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int n;
    string s, t;
    cin >> n >> s >> t;
    LL dp[26] = {};
    
    dp[s[0] - 'a'] = 1;
    for( int i = 1; i < s.size() - 1; ++i ) {
        dp[s[i] - 'a'] = ( dp[s[i] - 'a'] + dp[t[i] - 'a'] ) % MOD;

    }
    cout << dp[t[n - 1] - 'a'] << endl;

    return 0;
}

