#include <stdio.h>
 #include <ctype.h>
 #include <stdlib.h>




#define MAX_LINE_LENGTH 1000
#define MAX_ARITY 10


typedef struct te {
    char name;
    struct te * sub_terms[MAX_ARITY];
    int arity;
    int variable;
    int constant;
    struct te * parent;
} term;


typedef struct v_as {
    int variable;
    term * parent;
} variable_assignment;


typedef struct as {
    int variable;
    variable_assignment assigment;;
    struct as * rest;
} assignment;




void make_term( term * base, char * line, char ** stop)
{
    term* current_term = base;
    char * pos = line;
    int arg = 0; // a counter for determing which argument we are on.
    char temp[MAX_LINE_LENGTH];
    char * place;
    char ** stop_point;
    place = pos;
    stop_point = &place;
    

    if (isalpha(*pos) && isupper(*pos))
    {
	current_term->name = *pos;
	current_term->variable = 1;
	//fprintf(stderr, "Found a variable %c\n", *pos);
	stop[0] = pos+1;
	return;
    }
	
    if (isalpha(*pos) && islower(*pos)) 
    {
	current_term->name = *pos;
	
    }
	    

    if (*(pos+1) != '(')
    {
	current_term->constant = 1;
	//fprintf(stderr, "Found a constant %c\n", *pos);
	stop[0] = pos+1;
	return;
    }
    else
    {
	//fprintf(stderr, "Found a function %c\n", *pos);
    // there are arguments.  First we call make_term to get the first argument
    
    current_term->arity=1;
    current_term->sub_terms[arg] = (term *)calloc(1,sizeof(term));
    if ( current_term->sub_terms[arg] == NULL)
    {
	fprintf(stderr, "Malloc Failure\n");
	exit(1);
    }
    current_term->sub_terms[arg]->parent = current_term;
    pos = pos+2;// to skip the function name and the (
    while (1)
    {
	
	//fprintf(stderr, "looking for arg %d from %s\n",arg,pos);
	make_term( current_term->sub_terms[arg],pos,stop_point);
	place = stop_point[0];
	
	//fprintf(stderr, "After make_term place is %s\n",place);
	if (*place == ',')
	{
	    //fprintf(stderr, "Found a comma, so looking for another argument from %s\n",place);
	    current_term->arity++;
	    arg++;
	    current_term->sub_terms[arg] = (term *)calloc(1,sizeof(term));
	    if ( current_term->sub_terms[arg] == NULL)
	    {
		fprintf(stderr, "Malloc Failure\n");
		exit(1);
	    }
	    current_term->sub_terms[arg]->parent = current_term;
	    
	    
	}
	else
	{
	    if  (*place == ')')
	    {
		//fprintf(stderr, "Found a ), so arity is %d continuing on from %s\n",current_term->arity,place+1);
		stop[0] = place+1;

		break;

	    }
	    else
	    {
		fprintf(stderr, "Parse error\n");
		exit(1);
	    }}
	pos = place+1; // to skip the ,
    }
    }
}



void print_term(term * cl)
{
    int i;
    if (isalpha(cl->name) && isupper(cl->name))
    {
	fprintf(stderr,"%c",cl->name);
	return;
    }

    if (isalpha(cl->name) && islower(cl->name))
    {
	if (cl->constant == 1)
	    	fprintf(stderr,"%c",cl->name);
	else
	{
	fprintf(stderr,"%c(",cl->name);
	for(i = 0; i < cl->arity; i++)
	{
	    print_term(cl->sub_terms[i]);
	    if (i +1 < cl->arity)
		fprintf(stderr, ",");

	}
	fprintf(stderr, ")");
	return;
	}}


}


int unify(term * term_one,term * term_two,assignment * ass)
{

    return(0);
}

 int main(int argc, char **argv)
{

    char * read_val;
    char  line_one[MAX_LINE_LENGTH];
    char  line_two[MAX_LINE_LENGTH];
    

// read in from stdin

    if (NULL == fgets(line_one,MAX_LINE_LENGTH,stdin))
    {
	fprintf(stderr, "No input line\n"); 
	exit(1);
    }
    if (NULL == fgets(line_two,MAX_LINE_LENGTH,stdin))
    {
	fprintf(stderr, "No 2nd input line\n"); 
	exit(1);
    }
    

    // work out the lenght of the two terms

    int length_one =1;
    int length_two = 1;
    char * pos;
    char * * place;
    place = &pos;
    term * term_one;
    term_one = calloc(1,sizeof(term));
    term * term_two;
    term_two = calloc(1,sizeof(term));
    if (term_one == NULL || term_two == NULL)
    {
	fprintf(stderr, "Malloc failure\n");
	exit(1);
    }
   
    pos = line_one;
    int negative = 0;
   
    make_term(term_one,line_one,place);
    make_term(term_two,line_two,place);
    

    print_term(term_one);   
    fprintf(stderr, "\n");   
    fprintf(stderr, "\n");
    print_term(term_two); 
    fprintf(stderr, "\n");
    fprintf(stderr, "\n");




//

}