You mean too few. This is the same code formatted as closely as I could figure.
This is very twisted code, if there's any doubt as to whether or not the reader will understand on the first pass, be sure to comment it. Your loop structure is very hard to follow since each loop's testing condition is based on the counter for the previous loop.
int num_files, file_nums = '0', loop;
printf("input amount of files:> ");
scanf("%d",&file_nums[loop]; /*how do I know what to do?*/
for(num=0;num<fnumber;num++) /* fnumber=3 */ //fnumber means?
if(file_nums[loop] == file_nums[num]) /*huh? tell me what's happening here*/
if(seen != 0) /* be explicit */
} /*you forgot this bracket*/
Out of curiosity, what are you trying to do with this code? I can't figure it out.