import java.util.*;
import java.util.regex.*;
class Ideone {
public static void main
(String[] args
) { String str
= "word1_word2-word3"; str = Pattern.compile("[-_]([a-zA-Z0-9])")
.matcher(str)
.replaceAll(mr -> mr.group(1).toUpperCase());
}
}
aW1wb3J0IGphdmEudXRpbC4qOwppbXBvcnQgamF2YS51dGlsLnJlZ2V4Lio7CgpjbGFzcyBJZGVvbmUgewoJcHVibGljIHN0YXRpYyB2b2lkIG1haW4gKFN0cmluZ1tdIGFyZ3MpIHsKICAgICAgICBTdHJpbmcgc3RyID0gIndvcmQxX3dvcmQyLXdvcmQzIjsKCQlzdHIgPSBQYXR0ZXJuLmNvbXBpbGUoIlstX10oW2EtekEtWjAtOV0pIikKICAgIC5tYXRjaGVyKHN0cikKICAgIC5yZXBsYWNlQWxsKG1yIC0+IG1yLmdyb3VwKDEpLnRvVXBwZXJDYXNlKCkpOwogICAgICAgIFN5c3RlbS5vdXQucHJpbnRsbihzdHIpOwoJfQp9Cg==