C :: Create A File And Save Text In It In PDF Format

My objective is to create a file and save some text in it. But the twist is that file should be created in pdf format.

I have written following code:

Code:
#include<stdio.h>

Code:
int main() { FILE *fp;
char ch;
fp=fopen("file.pdf","w");
fprintf(fp, "%PDF-1.3"); //to initiate data storage in pdf file
printf(" Enter data to be stored in to the file:");
while((ch=getchar())!=EOF)
putc(ch,fp);
fclose(fp);
return 0;}

Now my file is created in pdf format, but when I open it by double click on it, it is not open and gives the message like: "Error in opening document. This file is damaged and could not be repaired."