#include <bits/stdc++.h>
using namespace std;

struct Node {
    char sign;       // 运算符，叶子节点为 '?'
    long long num;   // 数字
    Node* left;
    Node* right;
    
    Node(): sign('?'), num(-1), left(nullptr), right(nullptr) {}
    Node(char s): sign(s), num(-1), left(nullptr), right(nullptr) {}
    Node(long long n): sign('?'), num(n), left(nullptr), right(nullptr) {}
};

// 快速幂，整数
long long fastpow(long long base, long long exp){
    long long res = 1;
    while(exp > 0){
        if(exp & 1) res *= base;
        base *= base;
        exp >>= 1;
    }
    return res;
}

// 运算优先级
int level(char c){
    switch(c){
        case '+': case '-': return 1;
        case '*': case '/': return 2;
        case '^': return 3;
        default: return 0;
    }
}

// 找到最外层优先级最低的运算符
int findexp(const string &s, int l, int r){
    int pos = -1;
    int minLevel = 114514;
    int balance = 0; // 括号深度
    for(int i = r; i >= l; --i){ // 右结合，优先找右边
        if(s[i] == ')') balance++;
        else if(s[i] == '(') balance--;
        else if(balance == 0 && level(s[i]) > 0){
            if(level(s[i]) <= minLevel){
                minLevel = level(s[i]);
                pos = i;
            }
        }
    }
    return pos;
}

// 字符串转整数
long long toNum(const string &s, int l, int r){
    long long tmp = 0;
    while(l <= r && isspace((unsigned char)s[l])) l++;
    while(r >= l && isspace((unsigned char)s[r])) r--;
    if(l > r) return 0;
    for(int i = l; i <= r; ++i){
        if(!isdigit(s[i])) return 0;
        tmp = tmp * 10 + (s[i] - '0');
    }
    return tmp;
}

class Expression {
public:
    string exp;
    Node* root;
    long long result;
    bool isValid;
    
    Expression(const string &s): exp(s), root(nullptr), result(0), isValid(true) {}

    Node* build(const string &s, int l, int r){
        while(l <= r && s[l] == ' ') l++;
        while(l <= r && s[r] == ' ') r--;
        if(l > r) return nullptr;

        // 外层括号处理
        if(s[l] == '(' && s[r] == ')'){
            int balance = 0;
            bool hasOuter = true;
            for(int i = l; i <= r; ++i){
                if(s[i] == '(') balance++;
                else if(s[i] == ')') balance--;
                if(balance == 0 && i < r){
                    hasOuter = false;
                    break;
                }
            }
            if(hasOuter) return build(s, l+1, r-1);
        }

        int pos = findexp(s, l, r);
        if(pos == -1){
            long long val = toNum(s, l, r);
            return new Node(val);
        }

        Node* tmp = new Node(s[pos]);
        tmp->left = build(s, l, pos-1);
        tmp->right = build(s, pos+1, r);
        return tmp;
    }

    long long calc(Node* r, bool &v){
        if(!r) return 0;
        if(r->sign == '?') return r->num;

        long long left = calc(r->left, v);
        long long right = calc(r->right, v);

        switch(r->sign){
            case '+': return left + right;
            case '-': return left - right;
            case '*': return left * right;
            case '/':
                if(right == 0){ v = false; return 0; }
                return left / right;
            case '^':
                if(right < 0){ v = false; return 0; }
                return fastpow(left, right);
            default: return 0;
        }
    }

    void calc(){
        isValid = true;
        result = calc(root, isValid);
    }
};

int main(){
    string s;
    while(getline(cin, s)){
        Expression tree(s);
        tree.root = tree.build(s, 0, s.length()-1);
        tree.calc();
        if(tree.isValid) cout << tree.result << endl;
        else cout << "INVALID" << endl;
    }
    return 0;
}