1455.check if a word occurs as prefix of any word in a sentence

class Solution {
    public int isPrefixOfWord(String sent, String sea) {
        int c=-1;
        String sentence[]=sent.split("\\s+");
        boolean flag=true;
        for(int i=0;i<sentence.length;i++){
        
            if(sentence[i].length()<sea.length()){ continue;}
            for(int j=0;j<sentence[i].length();j++){
              if(j==0 && sentence[i].substring(j,j+sea.length()).equals(sea)){
                c=i;
                flag=false;
                break;
              } 
        }
        if(flag==false){ break;}
        }
       return c==-1?c:c+1;
    }
}