#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main(void) {
	int hrs, mins;

	scanf("%02d:%02d", &hrs, &mins);

	if (mins < 55)
		printf("%02d:%02d\n", hrs, mins + 5);
	else {
		if (hrs == 23)
			printf("00:%02d\n", mins - 55);
		else
			printf("%02d:%02d\n", hrs + 1, mins - 55);
	}

	return 0;
}