# include <stdio.h>
# include <string.h>
# define MAX 50
int a(char*s){
    int b[MAX], c = -1;
    int d = 0;
    for(int i = 0;i<n;i++){
        if(s[i] == '(') {
            b[++c] = 0;
            }else if (s[i] == '0'){
                if (c == -1) return -1;
                int val = b[c --];
                int add = (val == 0) ? 1:2*val;
                if ( c == -1)
                score += add;
                else
                a[c] += add;
            }else {
                return -2;
            }
    }
    return (c == -1) ? d : -1;
}
int main(){
    char s[MAX];
    scanf("%s", s);
    int x = a(s);
    if (x == -2){
        printf("Invalid input\n");
    }else if (x == -1){
        printf("Invalid input\n");
    }else {
        printf("%d\n",x);
    }
    return 0;
}