#include "stdio.h"
#include "stdlib.h"
#include <string.h>


typedef struct rule1{
    char *a;
    char *b;
}ru1;

typedef struct rule2 {
    char *a;
    char *b;
}ru2;

int main(){

    int k = 0;

    ru1 r1;
    r1.a = (char*)malloc(1 * sizeof(char)); r1.a = "A";
    r1.b = (char*)malloc(2 * sizeof(char)); r1.b = "AB" ;
    ru2 r2;
    r2.a = (char*)malloc(1 * sizeof(char)); r2.a = "B";
    r2.b = (char*)malloc(1 * sizeof(char)); r2.b = "A";


    char *sentence=(char*)malloc((k+1) * sizeof(char));
    sentence = "A";

    char *nextSentence ;
    char*ns;

    for (int i = 0; i < strlen(sentence);++i)
    {
        char current = sentence[i];
        if (current == r1.a)
        {
            k++;
            strcat(nextSentence, r1.b);
        }
        else if (current == r2.a)
        {
            strcat(nextSentence, r2.b);
        }
        sentence = (char*)realloc(sentence, (k + 1) * sizeof(char));
        sentence = nextSentence;
    }

    printf("%s\n", sentence);

}