world powers will meet in the coming days to discuss implementing a six-month agreement on iran's nuke prarm. rouhani said the deal has already benefitted his country's economy. >>> remembering nelson mandela. today marks the beginning of a week of remembrance. they have a day of prayer and reflection. earlier today the mandela foundation held a service. services like this were held throughout the country and really around the world. alan joins us life from south africa. alan, how are people paying tribute to mandela? from what i hear and see behind is any indication, they're doing it by celebrating. >> reporter: absolutely, richelle. the folks here in soweto are handling the party end of that equati equation. they've been doing it for days now and they'll go long into the night, too, and through the wee hours. it's a tremendous scene. for the more sub dued and reflective part of the formula, the national day of prayer. we attended mass at a huge catholic church not far from him. the population of the congregation in church today, the sounds of soweto, of a nation on what is not just another