/* prog5.4.c */
#include <stdio.h>

char *a; int i;
int eval()
  { int x = 0;
    while (a[i] == ' ') i++;
    if (a[i] == '+')
      { i++; return eval() + eval(); }
    if (a[i] == '*')
      { i++; return eval() * eval(); }
    while ((a[i] >= '0') && (a[i] <= '9')) 
      x = 10*x + (a[i++]-'0'); 
    return x;
  }

int main(int argc, char *argv[])
{
  a=argv[1];
  printf("%d\n", eval());
  return 0;
}