GetNth function for a linked list

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C

I am new to the concept of linked list and I need some help. I am writing a code which first builds a linked list and then function which gives the value of nth data in the list. But the code doesn't run. I am using Codeblocks so it doesn't tell the exact error, the process simple terminates. I cant understand why. Any help would be highly appreciated. Here's the code:

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

struct node{
    int data;
    struct node* ptr;
};
void push(struct node**,int);
void build(struct node**);
int getn(struct node*, int);

int main(){
    int n;
    struct node first;
    struct node* head;
    *head = first;
    first.data = 1;
    first.ptr = NULL;
    build(&head);
    n=getn(head,1);
    return 0;
}


void build(struct node** send){
    push(send,344);
    push(send,65);
    push(send,44);
}

void push (struct node** a, int datum){
    struct node* temp;
    temp = malloc(sizeof(struct node));
    temp->data = datum;
    temp->ptr =  *a;
    *a = temp;
}

int getn(struct node* top, int index){
    int n,k;
    struct node* current = top;
    for(n=0; n<index;n=n+1){
        k = current->data;
        current = current->ptr;
    }
    return k;
}