> #include <stdio.h>
> void main()
> {
> 	long input,i,save;
> 	scanf("%ld",&input);
> 	while(input!=0){
> 		if(input==1)printf("0\n");
> 		else {
> 			save=input;
> 			if(input%2==0)save/=2;
> 			while(input%2==0)input/=2;
> 			for(i=3;input!=1;i=i+2){
> 				if(input%i==0)save=save*(i-1)/i;
> 				while(input%i==0)input/=i;
> 			}
> 			printf("%ld\n",save);
> 		}
> 		scanf("%ld",&input);
> 	}
> }