#include <bits/stdc++.h>
 
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
 
mt19937 rng((int) chrono::steady_clock::now().time_since_epoch().count());
    
const int MOD = 1e9 + 7;
const int MAXN = 2e2 + 5;
const int MAXT = 3e5 + 10;
const ll INF = 2e18;

int a[MAXN], t[MAXN];

int dp[MAXN][MAXT], sp[MAXN][MAXT];

ll pot[MAXN];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    pot[0] = 1;
    for(int i = 1; i < MAXN; i++) {
        pot[i] = pot[i - 1] * 2;
        pot[i] %= MOD;
    }
    int n, tot;
    cin >> n >> tot;
    ll resp = 0;
    dp[0][0] = 1;
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    for(int i = 1; i <= n; i++) {
        cin >> t[i];
        for(int j = 0; j + t[i] <= tot; j++) {
            dp[i][j + t[i]] += dp[i - 1][j];
            dp[i][j + t[i]] %= MOD;
            resp += (dp[i - 1][j] * a[i]) % MOD * pot[n - i];
            resp %= MOD;
        }
        for(int j = 0; j <= tot; j++) {
            dp[i][j] += dp[i - 1][j];
            dp[i][j] %= MOD;
        }
    }
    for(int i = 0; i <= n; i++) {
        for(int j = 0; j <= tot; j++) {
            dp[i][j] = 0;
        }
    }
    dp[n + 1][0] = 1;
    for(int i = n; i >= 1; i--) {
        for(int j = 0; j + t[i] <= tot; j++) {
            dp[i][j + t[i]] += dp[i + 1][j];
            dp[i][j + t[i]] %= MOD;
        }
        for(int j = 0; j <= tot; j++) {
            dp[i][j] += dp[i + 1][j];
            dp[i][j] %= MOD;
        }
    }
    int sp = 0;
    for(int i = 1; i <= n; i++) {
        sp += t[i];
        ll mn = 0;
        for(int j = 0; j + sp <= tot; j++) {
            mn += dp[i + 1][j];
            mn %= MOD;
        }
        resp += (mn * a[i]) % MOD * pot[i - 1];
        resp %= MOD;    
    }
    cout << resp << '\n';
    return 0;
}