SOURCE

var line = 'nhrwlbcc8m7c5hih9mhalw98k0322wf2jjm47kk3ntm9snfrflzzundn7d608usy049asxalzjk7izj6amcqhr8uubc04g52mcjboj2fmge2l6iarizfu4yve5o4i3srf5zgqbg82ckcotdeqp760mc9gzei5dzk5gj9x9yj05o3hle0ii64krkkp5i7blh7nbu3gu5vgi2scyn4yqx3z4vcjbyzhnqkh887izotjkg2l0mit0k14vyn39'
var a = {}
for(var i = 0;i<line.length;i++){
    if(a[line.charCodeAt(i)] === undefined)a[line.charCodeAt(i)] = 0
    a[line.charCodeAt(i)] += 1
}
console.log(a)
var line2= 't'
var o = line2.charCodeAt(0)
//console.log(line2)
if(a[o]===undefined){
    console.log(0)
}else if(o>=97&&o<=122){
    //console.log(line2.charCodeAt(0)-32)
    if(a[o-32]===undefined)console.log(a[o])
    else console.log(a[o]+a[o-32])
}else if(o>=65&&o<=90){
    if(a[o+32]===undefined)console.log(a[o])
    else console.log(a[o]+a[o+32])
}else{
    console.log(a[o])
}
const jj = [...new Set(line)]
console.log(jj)