// dfmt off
T lread(T=long)(){return readln.chomp.to!T;}T[] lreads(T=long)(long n){return iota(n).map!((_)=>lread!T).array;}
T[] aryread(T=long)(){return readln.split.to!(T[]);}void arywrite(T)(T a){a.map!text.join(' ').writeln;}
void scan(L...)(ref L A){auto l=readln.split;foreach(i,T;L){A[i]=l[i].to!T;}}alias sread=()=>readln.chomp();
void dprint(L...)(lazy L A){debug{auto l=new string[](L.length);static foreach(i,a;A)l[i]=a.text;arywrite(l);}}
static immutable MOD=10^^9+7;alias PQueue(T,alias l="b<a")=BinaryHeap!(Array!T,l);import std;
// dfmt on

void main()
{
    long N, M, K;
    scan(N, M, K);
    auto A = aryread();
    auto B = aryread();
    auto S = [0L] ~ B ~ [0L];
    foreach (i; 0 .. M)
    {
        S[i + 1] += S[i];
    }
    long as;
    long ans;
    foreach (i; 0 .. N + 1)
    {
        long ok = 0;
        long ng = M + 1;
        while (1 < (ng - ok))
        {
            long j = (ok + ng) / 2;
            if (S[j] <= K - as)
            {
                ok = j;
            }
            else
            {
                ng = j;
            }
        }
        dprint(i, ok);
        if (as + S[ok] <= K)
            ans = ans.max(i + ok);
        if (i < A.length)
            as += A[i];
    }
    writeln(ans);
}
