#include

int main()
{
int h, m;

scanf("%d %d" , &h, &m);

if (m < 45)
{
if (h == 0)
h = 23;
else
h = h - 1;

m = m + 60 - 45;
}
else
m = m - 45;

printf("%d : %d", h, m);

}