How many matches did Radamel Falcao García play when he was in the Colombia National Under-20 Football Team?
SELECT ?value WHERE { wd:Q138172 p:P54 ?s . ?s ps:P54 wd:Q1641573 . ?s pq:P1350 ?value}
radamel falcao: Q138172 colombia u20 soccer team: Q1641573