The only way is to go to the last stop, a city in the North, Kosti.

CENTERFORSECURITYPOLICY: simon_deng

When we arrive in Kosti it turns out he has three other kids that I didn't know.

CENTERFORSECURITYPOLICY: Center For Security Policy

Before we left Kosti for the village, he got rid of two kids.

CENTERFORSECURITYPOLICY: Center For Security Policy

Between 12, 000 and 15, 000 South Sudanese are at the Kosti way station, "many of whom have been waiting with their entire house holdings for months for transport to South Sudan, " a U.N. statement said.

CNN: U.N.: Thousands stranded at Sudan way station

"As those awaiting repatriation from Kosti to South Sudan are in a vulnerable position and lack many basic services including adequate shelter, vital and quick collaboration is needed from Sudan and South Sudan to alleviate the hardship of those stranded in Kosti, " Ali Al-Za'tari, the U.N.

CNN: U.N.: Thousands stranded at Sudan way station