/// The text splitting

#include<bits/stdc++.h>
using namespace std;

int main()
{
    char s[101];
    int n,p,q,i,j,mul=1,m,chk,chk2;
    cin>>n>>p>>q;
    cin>>s;
    int sum =0;
    while(sum<n)
    {
        sum = mul*p + mul* q;
        mul++;
    }
    if(sum==n)
    {
        mul--;
        mul = mul*2;
        cout<<mul<<endl;
        i = 0;
        m=0;
        mul= mul/2;
        while(mul)
        {

        for(i; i<(m+p);i++)
        cout<<s[i];
        m = i;
        cout<<endl;
        for(j=i;j<(m+q);j++)
            cout<<s[j];
        m = i;
        cout<<endl;
        mul--;
        }
    }
    else
    {
        if(p>q)
            {
              chk = q;
              chk2 = p;
            }

        else
            {
              chk = p;
              chk2 = q;
            }
        if(n%chk==0)
        {
            mul = n/chk;
            cout<<mul<<endl;

                j=1;
                for(i=0;s[i]!='\0';i++,j++)
                {
                    cout<<s[i];
                    if(j==chk)
                    {
                        cout<<endl;
                        j = 0;
                    }
                }
        }
        else if(n%chk2==0)
        {
           mul = n/chk2;
            cout<<mul<<endl;

                j=1;
                for(i=0;s[i]!='\0';i++,j++)
                {
                    cout<<s[i];
                    if(j==chk2)
                    {
                        cout<<endl;
                        j = 0;
                    }
                }
        }
        else
        cout<<"-1";
    }
    return 0;

}