What is the smallest possible radius?
{'header': ['Star (Pismis24-#)', 'Spectral type', 'Magnitude (M bol )', 'Temperature (K)', 'Radius (R ☉ )', 'Mass (M ☉ )'], 'page_title': 'NGC 6357', 'page_id': '', 'types': ['text', 'text', 'text', 'real', 'real', 'real'], 'id': '1-10432351-1', 'section_title': 'Pismis 24', 'caption': 'Prominent stars in Pismis 24', 'rows': [['1NE', 'O3.5 If *', '−10.0', '42000', '17', '74'], ['1SW', 'O4 III', '−9.8', '41500', '16', '66'], ['2', 'O5.5 V(f)', '−8.9', '40000', '12', '43'], ['3', 'O8 V', '−7.7', '33400', '9', '25'], ['10', 'O9 V', '−7.2', '31500', '8', '20'], ['12', 'B1 V', '−5.3', '30000', '4', '11'], ['13', 'O6.5 III((f))', '−8.6', '35600', '12', '35'], ['15', 'O8 V', '−7.8', '33400', '10', '25'], ['16', 'O7.5 V', '−9.0', '34000', '16', '38'], ['17', 'O3.5 III', '−10.1', '42700', '17', '78'], ['18', 'B0.5 V', '−6.4', '30000', '6', '15']], 'name': 'table_10432351_1'}