#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define forn(i,a,b) for( int i = (a); i < (b); i++ )
#define rep(i,n) forn(i,0,n)
#define repe(i,n) for( i = 0; i < (n); i++ )
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pdd pair<double,double>

const int MXP = 19;
const int MXN = 100100;

vector< pair<ll,int> > val [MXP];

int ans [MXN];
int anc;

int main()
{

    //freopen("input.txt", "r", stdin);    freopen("output.txt", "w", stdout);
    freopen("exact.in", "r", stdin);    freopen("exact.out", "w", stdout);

    ll x;
    int n;
    scanf("%lld%d", &x, &n);
    rep(i,n){
        int k,q;
        scanf("%d%d", &k, &q);
        ll cur = pow(10,k) * q;
        val[k].pb( {cur,i} );
    }
    rep(i,MXP) sort(val[i].begin(), val[i].end());

    ll rest = 0;
    ull cpow = 1;
    vector< pair<ll,int> > tmp;
    vector< pair<ll,int> > poss;
    int curp = -1;
    while(x){
        curp++;
        cpow*=10;
        tmp.clear();
        tmp.resize( poss.size() + val[curp].size() );
        merge(poss.begin(), poss.end(), val[curp].begin(), val[curp].end(), tmp.begin());
        tmp.swap(poss);
        ll cur = x%cpow;
        x -= cur;
        if(rest>=cur){
            rest -= cur;
            continue;
        }
        cur -= (rest/(cpow/10)) * (cpow/10);
        while(!poss.empty()){
            pair<ll,int> q = poss.back();
            ans[anc++] = q.se;
            poss.pop_back();
            if(cur <= q.fi){
                rest += q.fi - cur;
                cur = 0;
                break;
            }
            else{
                cur -= q.fi;
            }
        }
        if(cur<=rest){
            rest -= cur;
        }
        else{
            printf("-1");
            return 0;
        }
    }
    printf("%d\n", anc);
    rep(i,anc) printf("%d ", ans[i]+1);

    return 0;
}