The following JS function provides the sum of the letters in some text (a = 1, b = 2, ... z = 26):
lettersum = t => t.toLowerCase().split("").filter(s => s.match(/[a-z]/)).map(l => l.codePointAt(0) - 96).reduce((a, b) => a + b);This one computes be mod m:
modpow = (b, e, m) => {
let r = 1;
while (e > 0) {
r = (r * b) % m;
e--;
}
return r;
};The following, using those functions, with my preferred name and surname in place of "text", outputs 1141:
const s = lettersum("text");
console.log(modpow(s, s, 8191));