Definition: In this task, you are given a text from a post. Your task is to find all of the proper nouns and label them. The labels are <B-PER>, <I-PER> for persons; <B-ORG>, <I-ORG> for organizations; <B-LOC>, <I-LOC> for locations; and <B-MISC>, <I-MISC> for other nouns. The capital 'B' denotes the first word of a proper noun phrase. The capital 'I' denotes all following words of the same noun phrase. If a word is not a part of a proper noun phrase, do not label it.
Input: A South African boy is writing back to an American girl whose message in a bottle he found washed up on President Nelson Mandela 's old prison island . 

A South <B-MISC> African <I-MISC> boy is writing back to an American <B-MISC> girl whose message in a bottle he found washed up on President Nelson <B-PER> Mandela <I-PER> 's old prison island . 