建议加强数据

#include<bits/stdc++.h>

#define int long long
#define rep(i,l,r)for(int i = l;i <= r;i ++)
#define dep(i,r,l)for(int i = r;i >= l;i --)

using namespace std;

mt19937 rnd(time(0));

inline int random(int l,int r){return rnd() % (r - l + 1) + l;}

char s[600];

signed main(){
	freopen("data.txt","w",stdout);
	int n = 50000;
	cout<<n<<endl;
	int now = 0;
	rep(i,0,599)s[i] = (char)('a' + random(0,1));
	rep(i,1,n){
		cout<<s[now]<<endl;
		now ++;
		if(now == 600)now = 0;
	}
}