#include<stdio.h>
int isSpecifiedChar(char* p);
void swap(char* first, char* end);
int Scramble(char* sentence);


int Scramble(char* sentence){
    int counter = 0;
    int i = 0;
    char* headPointer = sentence;
    int len = strlen(sentence);
    char* tailPointer = sentence + len -1;
    char* head = sentence;
    
    while(headPointer != tailPointer){
        //get the headPointer with specified digit
        while(!isSpecifiedChar(headPointer)){
            if(headPointer == tailPointer){
                return counter;
            }
            headPointer++;
        }
        //get the tailPointer with specified digit
        while(!isSpecifiedChar(tailPointer)){
            if(headPointer == tailPointer){
                return counter;
            }
            tailPointer--;
        }
        
        if(headPointer == tailPointer){
            return counter;
        }
        swap(headPointer, tailPointer);
        counter++;
        headPointer++;
        tailPointer--;
        
    }
    
    return counter;
    
    
    

}

int isSpecifiedChar(char* p){
    if(*p == 33|| (*p >= 36 && *p <= 39) || *p == 44 || *p == 46 || (*p >= 48 
    && *p <= 59 )|| *p == 63 || (*p>=65 && *p <=90)){
        return 1;
    }
    return 0;
}

void swap(char* first, char* end){
    char temp;
    temp = *first;
    *first = *end;
    *end = temp;
}