#include<bits/stdc++.h>
using namespace std;
int main(){
    freopen("data.in","w",stdout);
    srand( (unsigned int) time( NULL ));
    int n=rand()%20;
    printf("%d\n",n);
    for (int i=1;i<=n;i++) printf("%d ",rand()%20+50);
    fclose(stdout);
}