give string word return sum number vowel e o u substre wordA substre contiguous nonempty sequence character stringnote due large constraint answer fit sign 32bit integer please careful calculation example 1input word abaoutput 6explanation all possible substring ab aba b ba b 0 vowel ab ba 1 vowel aba 2 vowel ithence total sum vowel 0 1 1 1 1 2 6 Example 2input word abcoutput 3explanation all possible substring ab abc b bc c ab abc 1 vowel b bc c 0 vowel eachhence total sum vowel 1 1 1 0 0 0 3example 3input word ltcdoutput 0explanation there vowel substre ltcd Constraints1 wordlength 105word consist lowercase english letter