AMRITA5

// uzumaki naruto
#include <bits/stdc++.h>
#define each(v,c)  for(typeof((c).begin()) v = (c).begin(); v != (c).end(); ++v)
#define pb         push_back
#define mp         make_pair
#define sz(a)      ((int)(a.size()))
#define all(a)     (a).begin(), (a).end()
#define fi         first
#define se         second
#define TRACE
using namespace std;

#ifdef TRACE
#define debug(a,n)    cerr << "["; for(int i = 0; i < n; ++i) cerr << a[i] << " ";cerr << "\b]\n";
#define dbg(args...)  {debug1,args; cerr<<endl;}
#define pause()       cin.get();cin.get();

#else

#define debug(a,n)
#define dbg(args...)
#define pause()

#endif

struct debugger {
    template<typename T> debugger& operator , (const T& v) {
        cerr<<v<<" "; return *this;
    }
} debug1;

template <typename T1, typename T2>
inline ostream& operator << (ostream& os, const pair<T1, T2>& p) {
    return os << "(" << p.first << ", " << p.second << ")";
}

template<typename T>
inline ostream &operator << (ostream & os,const vector<T>& v) {
    bool first = true; os << "[";
    for (typename vector<T>::const_iterator ii = v.begin(); ii != v.end(); ++ii) {
        if(!first) os << ", ";
        os << *ii; first = false;
    }
    return os << "]";
}

typedef long long LL;
typedef pair<LL,LL> pii;
typedef vector<int> vi;

const LL mod = 1000000007;

pii f(LL n, LL dd){
    if (n == 1){
        LL ans = 0;
        for(int i = 0; i < dd; ++i)
            ans = (ans + i)%mod;
        return mp(ans,dd);
    }

    pii res = f(n/2,dd);
    LL sum = res.fi, cnt = res.se;

    pii nine = f(n/2,9LL);
    LL ans = 0;
    ans = (ans + cnt*(nine.fi))%mod;
    ans = (ans + (nine.se*sum)%mod )%mod;

    ans = (ans + cnt*(9LL*(n/2LL))%mod )%mod;
    ans = (ans + sum)%mod;

    ans = (ans + cnt*(dd*(n/2LL))%mod )%mod;
    ans = (ans + sum)%mod;

    LL new_cnt = 0;
    new_cnt = ((cnt * (nine.se+1))%mod + new_cnt)%mod;
    new_cnt = (new_cnt + cnt)%mod;

    LL a1 = 0LL, a2 = 0LL;
    if (n & 1){
        pii nn = f(n-1LL,9LL);
        for(LL i = 0; i < dd; ++i){
            a1 = (a1 + (i*(nn.se+1LL))%mod ) %mod;
            a1 = (a1 + nn.fi)%mod;
            a1 = (a1 + (9LL*(n-1LL))%mod )%mod;
            a2 = (a2 + (nn.se+1LL))%mod;
        }

        a1 = (a1 + ans)%mod;
        a1 = (a1 + (dd*cnt)%mod )%mod;
        a2 = (a2 + new_cnt)%mod;

        ans = a1;
        new_cnt = a2;
    }
    return mp(ans,new_cnt);
}

#define M 1000000007
long long dig[10004];
long long len[10004];
bool vis[10004][2];
long long dp[10004][2];
int m;

long long cal(int idx, int tight)
{
    if ( idx == m ) return 0LL;
    if ( vis[idx][tight] ) return dp[idx][tight];
    vis[idx][tight] = true;
    long long ans;
    if ( tight == 0 ) {
        pii tmp = f(len[idx],9LL);
        ans = (tmp.fi + ((tmp.se+1LL)*cal(idx+1,0))%M)%M;
        ans = (ans + (9LL*len[idx])%M)%M;
    }
    else {
        pii tmp = f(len[idx],dig[idx]);
        ans = (tmp.fi + (tmp.se * cal(idx+1,0))%M)%M;
        ans = (ans + (len[idx]*dig[idx])%M)%M;
        ans = (ans + cal(idx+1,1))%M;
    }
    dp[idx][tight] = ans;
    return ans;
}
int main()
{
    int t;
    cin >> t;
    while ( t-- ) {
        memset(vis,false,sizeof(vis));
        cin >> m;
        for ( int i = 0; i < m; i++ ){
            cin >> len[i] >> dig[i];
            len[i] = len[i]%M;
        }

        long long ans = cal(0,1);
        cout << ans << endl;
    }
    return 0;
}