let n = 1, m = 1;
let head = new Int32Array(100010).fill(-1); //head[x] == -1 为终点
let next = new Int32Array(100010);
let val = new Int32Array(100010);
let idx = 0;

let indegree = new Int32Array(100010); //入度
let q = new Int32Array(100010); //输出序列

//头部插入，添加 a -> b 的关系 
let addHead = (a, b) => {
    val[idx] = b;  //存放a的后续节点b
    next[idx] = head[a]; //next存放当前a的第一个后续节点，在val中的位置，next[x] == -1 为不存在
    head[a] = idx++; //存放新加入的a的后续节点，在val中的位置
    indegree[b]++; //b的入度加1
};


let topSort = () => {
    let h = 0, t = -1;
    //找到入度为0的起始点
    for (let i = 1; i <= n; i++) {
        if (indegree[i] === 0) q[++t] = i;
    }
    while (h <= t) {
        let tmp = q[h++];
        for (let i = head[tmp]; i !== -1; i = next[i]) {
            //若存在tmp的后续节点，即i !== -1，
            let j = val[i];
            //后续节点j的入度减1后，看是否遍历完成
            if(--indegree[j] === 0) q[++t] = j;
        }
    }
    return t == n - 1;
}

let buf = '';
process.stdin.on('readable', function () {
    let chunk = process.stdin.read();
    if (chunk) buf += chunk.toString();
});
let getInputNums = line => line.split(' ').filter(s => s !== '').map(x => parseInt(x));
let getInputStr = line => line.split(' ').filter(s => s !== '');
process.stdin.on('end', function () {
    buf.split('\n').forEach(function (line, lineIdx) {
        if (lineIdx === 0) {
            n = getInputNums(line)[0];
            m = getInputNums(line)[1];
        } else {
            let arr = getInputNums(line);
            addHead(arr[0], arr[1]);
            if (lineIdx === m) {
                if(topSort()){
                    console.log(q.slice(0, n).join(' ')); 
                }else{
                    console.log('-1');
                }
            }
        }
    });
});