// Simionescu Andrei, 2/21/2010
// http://infoarena.ro/problema/evaluare
// Dificultate: EASY->MEDIUM
// Categorii: Interpretare

#include <cstdio>
#include <vector>
using namespace std;

typedef vector<int> stiva;
#define top back
#define pop pop_back
#define push push_back

#define PLUS -1
#define MINUS -2
#define ORI -3
#define 

int pr(  )





int main(){
 freopen( "evaluare.in", "r", stdin );
 freopen( "evaluare.out", "w", stdout );

 printf( "%d\n", eval() );
  
 return 0;
}