"use strict"
const create = () => {
    const input = require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n");
    const res = {
        "list": input, "index": 0, "max": input.length,
        "hasNext": function() {return this.index < this.max},
        "next": function() { if (!this.hasNext()) {throw "ArrayIndexOutOfBoundsException";}else{return this.list[this.index++];}}
    };
    return res;
}
const o = create();
const next = () => o.next()
const nextInt = () => parseInt(o.next())
const nextStrArray = () => o.next().split(" ")
const nextIntArray = () => o.next().split(" ").map(el => parseInt(el))
const nextCharArray = () => o.next().split("")
const hasNext = () => o.hasNext()
const myout = (...x) => console.log(...x)
const Main = () => {
    let s = next()
    let m = ["01","02","03","04","05","06","07","08","09", "10","11","12"]
    const first = s.slice(0,2)
    const second = s.slice(3)
    if(m.includes(first) && m.includes(second)){
        console.log("AMBIGUOUS")
        return
    } else if (m.includes(first) && !m.includes(second)){
        console.log("MMYY")
        return
    } else if (!m.includes(first) && m.includes(second)){
        console.log("YYMM")
        return
    } else {
        console.log("NA")
        return
    }
}
Main()
