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

typedef long long ll;
map<char, int> mp = {{'+',1},{'-',1},{'*',2},{'/',2}};
stack<char> op;
stack<ll> num;

bool eval() {
    if(num.size() < 2) return false;
    ll a = num.top(); num.pop();
    ll b = num.top(); num.pop();
    if(op.size() < 1) return false;
    char c = op.top(); op.pop();
    switch(c) {
        case '+': num.push(b+a); break;
        case '-': num.push(b-a); break;
        case '*': num.push(b*a); break;
        case '/': num.push(b/a); break;
    }
    return true;
}

int main(){
    string s;
    cin>>s;
    bool flag = false;
    for(int i=0; i<s.size()-1; i++) {
        if(isdigit(s[i])) {
            ll k = 0;
            while(i < s.size() && isdigit(s[i])) {
                k = k * 10 + s[i] - '0';
                i ++;
            }
            i--;
            if(flag) {
                k = -k;
                flag = false;
            }
            num.push(k);
        } else if(s[i] == '(') {
            op.push(s[i]);
        } else if(s[i] == ')') {
            while(op.top() != '(') {
                if(!eval()) {
                    cout<<"NO";
                    return 0;
                }
            }
            op.pop();
        } else {
            if(s[i] == '-') { //判断是负数的负号，还是正常的减号
                if(i == 0 || s[i-1] == '+' ||
                    s[i-1] == '-' || s[i-1] == '*' ||
                    s[i-1] == '/' || s[i-1] == '(') {
                        flag = true;
                        continue;
                    }
            }
            while(op.size() && mp[op.top()] >= mp[s[i]]) {
                if(!eval()) {
                    cout<<"NO";
                    return 0;
                }
            }
            op.push(s[i]);
        }
    }
    while(op.size()) {
        if(!eval()) {
            cout<<"NO";
            return 0;
        }
    }
    ll ans = num.top();
    cout << ans;
    return 0;
}