import java.util.regex.MatchResult;
import java.util.regex.Pattern;
 
public class Main {
    public static void main(String args[]) {
        // find the occurance of 'CO' in the given string using stream API
        String str = "WELCOMEWELCOME";
        String substring = "CO";
 
        System.out.println(getSubstringCount(str, substring));
    }
    static long getSubstringCount(String str, String substring) {
        return Pattern.compile(substring)
                .matcher(str)
                .results()
                .map(MatchResult::group)
                .count();
    }
}

aW1wb3J0IGphdmEudXRpbC5yZWdleC5NYXRjaFJlc3VsdDsKaW1wb3J0IGphdmEudXRpbC5yZWdleC5QYXR0ZXJuOwoKcHVibGljIGNsYXNzIE1haW4gewogICAgcHVibGljIHN0YXRpYyB2b2lkIG1haW4oU3RyaW5nIGFyZ3NbXSkgewogICAgICAgIC8vIGZpbmQgdGhlIG9jY3VyYW5jZSBvZiAnQ08nIGluIHRoZSBnaXZlbiBzdHJpbmcgdXNpbmcgc3RyZWFtIEFQSQogICAgICAgIFN0cmluZyBzdHIgPSAiV0VMQ09NRVdFTENPTUUiOwogICAgICAgIFN0cmluZyBzdWJzdHJpbmcgPSAiQ08iOwogICAgICAgIAogICAgICAgIFN5c3RlbS5vdXQucHJpbnRsbihnZXRTdWJzdHJpbmdDb3VudChzdHIsIHN1YnN0cmluZykpOwogICAgfQogICAgc3RhdGljIGxvbmcgZ2V0U3Vic3RyaW5nQ291bnQoU3RyaW5nIHN0ciwgU3RyaW5nIHN1YnN0cmluZykgewogICAgICAgIHJldHVybiBQYXR0ZXJuLmNvbXBpbGUoc3Vic3RyaW5nKQogICAgICAgICAgICAgICAgLm1hdGNoZXIoc3RyKQogICAgICAgICAgICAgICAgLnJlc3VsdHMoKQogICAgICAgICAgICAgICAgLm1hcChNYXRjaFJlc3VsdDo6Z3JvdXApCiAgICAgICAgICAgICAgICAuY291bnQoKTsKICAgIH0KfQ==