/*   @JUDGE_ID:   1705PZ   579   C */
#include <stdio.h>
#include <math.h>

int main(){
int h,m;
float answer;
while(1){
	scanf("%d:%d",&h,&m);
	if(h == 0 && m == 0)
		break;
	answer = fabs(h * 30 - 5.5 * m);
	if(answer > 180)
		answer = 360 - answer;
	printf("%.3f\n",answer);
	}
return 0;
}
@END_OF_SOURCE_CODE