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

    void solve(int tc) {
        int N, A, B; cin >> N >> A >> B;
        if(N == 1) {
            cout << (A == B) << '\n';
            cout << A << ":" << B << '\n';
            return;
        }

        if(A + B >= N) {
            cout << 0 << '\n';
            int idx = 0;
            while(idx < N-2 and A)
                cout << "1:0" << '\n', A--, idx++;
            if(idx == N-2 and A)
                cout << A << ":0" << '\n', A = 0, idx++;
            while(idx < N-1 and B)
                cout << "0:1" << '\n', B--, idx++;
            if(idx == N-1 and B)
                cout << "0:" << B << '\n', B = 0, B++;
            return;
        } else {
            cout << N-A-B << '\n';
            int idx = 0;
            while(A) cout << "1:0" << '\n', A--, idx++;
            while(B) cout << "0:1" << '\n', B--, idx++;
            while(idx < N) cout << "0:0" << '\n', idx++;
            return;
        }
    }

    int main() {
        ios::sync_with_stdio(false), cin.tie(0);
        solve(0);
        cout.flush(); return 0;
    }