include[HTML_REMOVED]
int main()
{
int n;
scanf(“%d”,&n);
int h1,m1,s1,h2,m2,s2,time1,time2,h3,m3,s3,h4,m4,s4,d1,d2;
int time[n];
int i;
for(i=1;i<=n;i++){
d1=d2=0;
scanf("%d:%d:%d %d:%d:%d (+%d)",&h1,&m1,&s1,&h2,&m2,&s2,&d1);
time1=(d1*24*3600+h2*3600+m2*60+s2)-(h1*3600+m1*60+s1);
scanf("%d:%d:%d %d:%d:%d (+%d)",&h3,&m3,&s3,&h4,&m4,&s4,&d2);
time2=(d2*24*3600+h4*3600+m4*60+s4)-(h3*3600+m3*60+s3);
time[i]=(time1+time2)/2;}
for(i=1;i<=n;i++){
printf("%02d:%02d:%02d\n",time[i]/3600,time[i]/60%60,time[i]%60);
}
return 0;
}