#include <stdio.h>
#include <unistd.h>

main(int argc,char *argv[])
{
char encr[10];
int i,len,done=0,times=0;
int nologin=0;
char login[30];
char log[30];
char passwd[10];
char *pass;
FILE *fp;


while (times<3 && !done)
{
fp=fopen(argv[1],"r");
printf("Login:");
scanf("%s",log);

pass=getpass("Password:");

do {
	if (feof(fp)) {nologin=1;break;};
	fscanf(fp,"%s",login);
	fscanf(fp,"%s",passwd);
   }

while (strcmp(login,log));

if (nologin) printf("LOGIN NOT FOUND\n");
else
 {

   len=strlen(pass);

   for(i=0;pass[i];i++)
	encr[i]= (i==0) ? (pass[i]+pass[i+1]*len+len)%90+32
				    : (pass[i]+encr[i-1]+i)%90+32;
	

   encr[i]='\0';
   
   if (strcmp(passwd,encr)==0) {printf("OK\n");done=1;}
   else printf("Password Incorrect\n");
   }


times++;
}
}