#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <iostream>
#include <sstream>
#include <bitset>
using namespace std;
#define MP(a, b) make_pair(a, b)
#define VT vector
#define FI first
#define SE second
#define FOR(i, n) for (int i = 0; i < n; ++i)
#define REP(i, n) for (int i = 1; i <= n; ++i)
typedef long long ll;
typedef unsigned long long ull;

const char *P;
const ll mod = 1000000007;
ll expr();
ll term();

ll term() {
    ll x = 0;
    if (P[0] == 'S') {
        P += 2;
        x = expr();
        x = x * x % mod;
        P++;
    }
    else {
        char *endp;
        x = strtoll(P, &endp, 10);
        P = endp;
    }
    return x;
}

ll expr() {
    ll x = term();
    ll b;
    while (P[0] == '>' && P[1] == '>' && (P[2] == 'S' || isdigit(P[2]))) {
        P += 2;
        x >>= min(term(), 63LL);
    }
    return x;
}

int main() {
    string s;
    while (1) {
        getline(cin, s);
        if (s[0] == '#') break;
        s.erase(remove(s.begin(), s.end(), ' '), s.end());
        P = s.c_str();
        // cout << s << endl;
        cout << expr() << endl;
    }
    return 0;
}