If Mary and Greg are in a given country, the first column has the numbers someone trying to calling them would need to use. The second column has the numbers Mary and Greg would need to call outside of that country.

Country Code into country Code out of country
South Africa +27 00
Lesotho +266 00
Botswana +267 00
Zimbabwe +263 00
Zambia +260 00
Malawi +265 00
Tanzania +255 000; 005 to Kenya; 006 to Uganda
Rwanda +250 00
Uganda +256 000; 005 to Kenya; 007 to Tanzania
Kenya +254 000; 006 to Uganda; 007 to Tanzania
Ethiopia +251 00
Sudan +249 00
Egypt +20 00