#include <stdio.h>

int main(void){
	
	int pos=0;
	int mul = 0;
	int sum = 0;
	char symbol = '+';
	char s[20];
	scanf("%s", s);
	
	if(s[0] == '-'){
		symbol = '-';
		pos++;
	}else if(s[0] == '+'){
		pos++;
	}
	
	for( ; s[pos] != '\0' ; pos++ ){
		if( '0' <= s[pos] && s[pos] <= '9' ){
			int num = (int)(s[pos] - '0');
			mul = mul * 10 + num;
		}else{
			if(symbol == '+'){
				sum += mul;
				mul = 0;
			}else{
				sum -= mul;
				mul = 0;
			}
			
			if(s[pos] == '+'){
				symbol = '-';
			}else{
				symbol = '+';
			}
		}
	}
	
	if(symbol == '+'){
		sum += mul;
	}else{
		sum -= mul;
	}
	
	printf("%d\n", sum);
	return 0;
}