#include <iostream>

typedef std::string::const_iterator State;

int number(State& state){
    int res = 1;
    
    if(*state == '+'){
        ++state;
    }else if(*state == '-'){
        res = -1;
        ++state;
    }

    int _ = 0;
    for(;std::isdigit(*state);++state){
        _ = _ * 10 + *state - '0';
    }

    return res * _;
}

int expr(State& state){
    int a = number(state);
    
    if(*state == '+'){
        ++state;
        return a - number(state);
    }else if(*state == '-'){
        ++state;
        return a + number(state);
    }
}

int main(){
    std::string S;
    std::cin >> S;
    
    State state = S.begin();
    std::cout << expr(state) << std::endl;
}