#include #define ft first #define sc second #define lb lower_bound #define ub upper_bound #define pb push_back #define pt(sth) cout << sth << "\n" #define chmax(a, b) {if(ab) a=b;} #define moC(a, s, b) (a)=((a)s(b)+MOD)%MOD using namespace std; typedef long long ll; typedef pair P; static const ll INF=1e18; static const ll MAX=1e5+7; static const ll MOD=1e9+7; ll N; ll a[20], b[20]; ll dp[1<<18][20]; ll rec(ll S, ll v) { if(dp[S][v]>=0) return dp[S][v]; if(S==(1<>u&1) continue; if(v==N) { chmin(res, rec(S|1<> N; for(i=0; i> a[i] >> b[i]; b[i]-=a[i]; } memset(dp, -1, sizeof(dp)); pt(rec(0, N)); }