declare var require: any;
let lines: string[] = require("fs").readFileSync("/dev/stdin", "utf8").split("\n");
const [N] = lines[0].split(' ').map(Number);
const S = lines.slice(1, N + 1);
const ans = new Set(S.flatMap((s1, i) => S.map((s2, j) => i !== j ? s1 + s2 : null).filter(Boolean))).size;
console.log(ans);