"use strict";
    
const main = arg => {
    arg = arg.split("\n");
    const N = arg[0];
    
    arg.shift();
    const d = arg.sort((a,b)=>b-a);
    
    const set = new Set(d);
    console.log(set.size);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));