#include<stdio.h>
#include<string.h>
int main(){
    char str[105],stack[105];
    int top = -1,i;
    scanf("%s",str);
    for(i = 0; i < strlen(str); i++){
        char c = str[i];
        if(c == ' (' || c == '{' || c == '[')[
            stack[++top] = c;
        }
    else if(c == ')' || c == '}' || c == ']'){
        if(top == -1){
            printf("not balanced");
            return 0;
        }
        char topchar = stack[top--];
        if(( c == ')' && topchar!= '(') || (c == '}' && topchar!= '{') || (c == ']' && topchar!='[')){
            printf("not balanced");
            return 0;
        }
    }
        }
    if(top == -1);
    printf("balanced");
    else
    printf("not balanced");
    return 0;
}