EASY MONEY!!!

#include <iostream>
#include <algorithm>
#include <cstring>
#include <stack>
#include <sstream>

using namespace std;

typedef long long LL;

const int N = 1100, MOD = 1e9 + 7;

int n, m;
int k;
int e[N];
string f[N];
int fx[N], dfdx[N], h1 = -1, h2 = -1;
char op[N], h3 = -1;
//stack<int> fx, dfdx;
//stack<char> op;

void eval_adf()
{
    LL db = dfdx[h2]; h2 -- ;
    LL da = dfdx[h2]; h2 -- ;
    LL b = fx[h1]; h1 -- ;
    LL a = fx[h1]; h1 -- ;
    char c = op[h3]; h3 -- ;

    int y, dy;

    if ( c == '+' ) {
        y = (a + b) % MOD;
        dy = (da + db) % MOD; 
    }
    else if ( c == '-' ) {
        y = (a - b) % MOD;
        dy = (da - db) % MOD;
    }
    else {
        y = (a * b) % MOD;
        dy = (da * b + db * a) % MOD;
    }

    dfdx[ ++ h2] = dy;
    fx[ ++ h1] = y;
}

int main()
{
    cin >> n >> m;

    cin.get();

    string ss;

    getline(cin, ss);
    stringstream ssin;

    ssin << ss;

    int len = 0;
    string temp;

    while (ssin >> temp) f[len ++ ] = temp; 

    while (m -- ) {
        cin >> k;
        for ( int i = 1; i <= n; i ++ )
            cin >> e[i];

        for ( int i = 0; i < len; i ++ ) {
            string c = f[i];
            if ( c[0] == 'x') {
                int idx = stoi(c.substr(1));
                if ( idx != k ) {
                    fx[ ++ h1] = e[idx];
                    dfdx[ ++ h2] = 0;
                } else {
                   fx[ ++ h1] = e[idx];
                   dfdx[ ++ h2] = 1;
                }
            }
            else if ( (c[0] == '-' && c.size() > 1) || isdigit(c[0]) ) {
                int sum = stoi(c);
                fx[ ++ h1] = sum;
                dfdx[ ++ h2] = 0;
            }
            else {
                op[ ++ h3] = c[0];
                eval_adf();
            }
        }

        while ( h3 > -1 ) eval_adf();

        cout << ((dfdx[h2] % MOD) + MOD) % MOD<< endl;
    }

    return 0;
}