#include<stdio.h>
#include<math.h>

int adad(char c){
    return ((48 <= (int)c) && ((int)c <= 57));
}
int characterBeAdad(char c){
    return (int)c - 48;
}

int main(){
    int x;
    long long jam = 0;
    long long tavan;
    long long zarib = 1;
    scanf("%i\n",&x);
    while(1){
        char c; 
        
        scanf("%c",&c);
        if(c == '\n'){
            //printf("%lli %lli\n",zarib, tavan);
            jam += zarib * (int)pow(x,tavan) * 1LL;
            break;
        }
        if(adad(c)){
            zarib *= characterBeAdad(c);
            while(1){
                scanf("%c",&c);
                if(c == ' '){
                    break;
                }
                zarib *= 10;
                zarib += characterBeAdad(c);
            }
        }
        if(c == 'x'){
            scanf(" ^ %lli",&tavan);
        }
        if(c=='+'){
            //printf("%lli %lli\n",zarib, tavan);
            jam += zarib * (int)pow(x,tavan)  * 1LL;
            zarib = 1;
        }
        if(c=='-'){
            //printf("%lli %lli\n",zarib, tavan);
            jam += zarib * (int)pow(x,tavan)  * 1LL;
            zarib = -1;
        }
    }
    printf("%lli",jam);
}