#include <stdio.h>
int main(){
    //input
    int hh,mm;
    scanf("%d:%d",&hh,&mm);

    //time in 5 minute
    int t = (60*hh+mm+5)%1440;

    //output
    printf("%02d:%02d\n",(t-t%60)/60,t%60);
    return 0;
}