Программа компилируется без ошибок, но не запускается - C (СИ)

#include <stdio.h>
#include <malloc.h>
 
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
struct node 
{     char  word;        
int  count;       
struct node  *next;              
}; 

void add(struct node *b, struct node *start)
{
struct node *tem, *cur;
tem=(struct node* )malloc(sizeof(struct node ));
if(tem==NULL)
{printf("NO!\n");
}
tem->word=b->word;
tem->count=b->count;
tem->next=NULL;
 
if(start==NULL)
{start=tem;
}
else
{cur=start;
while(cur->next!=NULL)
{
cur=cur->next;
}cur->next=tem;
 
}
}
 
struct node* vvod(struct node *start)
{
struct node *b;
FILE *fp;
fp=fopen("in.txt", "r");
//fscanf(fp,"%s %d", b->word, &(b->count));
if(fp==NULL)
{printf("NO!\n");
}
while(b->word!=EOF && b->count!=EOF)
{ fscanf(fp,"%s %d", b->word, &(b->count));
add(b, start);
printf("%d %s",b->word, b->count);
}
return b;
}
 
int main()
{struct node *start;
struct node *b;
start=NULL;
b=vvod(start);
//print(start, b);
}
 
void print(struct node *start, struct node *b)
{ 
if(start==NULL)
{printf("NOO!\n");
}
b=start;
printf("\n");
while(b!=NULL)
{printf("%s %d",b->word, &b->count);
b=b->next;
}
}