문제 링크 : Make Three Strings Equal
/**
* @param {string} s1
* @param {string} s2
* @param {string} s3
* @return {number}
*/
var findMinimumOperations = function(s1, s2, s3) {
let i=0
while(i<s1.length && s1[i]===s2[i] && s2[i]===s3[i]){
i++
}
return i===0 ? -1 : s1.length-i+s2.length-i+s3.length-i
};