use std::collections::HashSet;


struct UnionFind {
    n: usize,
    parents: Vec<usize>,
    depths: Vec<usize>,
    chains: Vec<usize>,
}

impl UnionFind {
    fn new(n: usize) -> Self {
        UnionFind {
            n: n,
            parents: (0..n).collect(),
            depths: vec![0; n],
            chains: vec![1; n],
        }
    }

    fn equiv(&mut self, a: usize, b: usize) -> bool {
        self.find(a) == self.find(b)
    }
    
    fn unite(&mut self, a: usize, b: usize) {
        if self.equiv(a, b) { return; }
        let x = self.parents[a];
        let y = self.parents[b];
        if self.depths[x] > self.depths[y] {
            self.parents[x] = self.parents[y];
            self.chains[y] += self.chains[x];
        } else {
            self.parents[y] = self.parents[x];
            self.chains[x] += self.chains[y];
            if self.depths[x] == self.depths[y] {
                self.depths[x] += 1;
            }
        }
    }

    fn find(&mut self, a: usize) -> usize {
        if self.parents[a] == a { return a; }
        let p = self.find(self.parents[a]);
        self.parents[a] = p;
        p
    }

    fn chain_cnt(&mut self, i: usize) -> usize {
        let idx = self.find(i);
        self.chains[idx]
    }
}

fn merge(a: usize, b: usize, uf: &mut UnionFind, size: &mut Vec<usize>) {
    let pa = uf.find(a);
    let pb = uf.find(b);
    if pa == pb { return; }
    uf.unite(pa, pb);
    let p = uf.find(pa);
    if p == pa {
        size[pa] += size[pb];
        size[pb] = 0;
    } else {
        size[pb] += size[pa];
        size[pa] = 0;
    }
}

fn main() {
    let mut ndw = String::new();
    std::io::stdin().read_line(&mut ndw).ok();
    let ndw: Vec<usize> = ndw.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = ndw[0];
    let d = ndw[1];
    let w = ndw[2];
    let mut cuf = UnionFind::new(n);
    let mut wuf = UnionFind::new(n);
    let mut wsize = vec![1usize; n];
    for _ in 0..d {
        let mut ab = String::new();
        std::io::stdin().read_line(&mut ab).ok();
        let ab: Vec<usize> = ab.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
        let a = ab[0]-1;
        let b = ab[1]-1;
        cuf.unite(a, b);
    }
    for _ in 0..w {
        let mut ab = String::new();
        std::io::stdin().read_line(&mut ab).ok();
        let ab: Vec<usize> = ab.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
        let a = ab[0]-1;
        let b = ab[1]-1;
        merge(a, b, &mut wuf,&mut wsize);
    }

    let mut children = vec![vec![]; n];
    for i in 0..n {
        children[cuf.find(i)].push(i);
    }
    let mut result_map = vec![0usize; n];
    for i in 0..n {
        let parent = cuf.find(i);
        if i != parent { continue; }
        let mut temp = HashSet::new();
        for &v in children[i].iter() {
            temp.insert(wuf.find(v));
        }
        result_map[i] = temp.iter().map(|&v| wsize[v]).sum::<usize>();
    }
    let mut result = 0usize;
    for i in 0..n {
        result += result_map[cuf.find(i)];
    }
    println!("{}", result-n);
}