# include # include # include # include # include # include # include # include # include # include # include # include # include # include # include # include # include # include using namespace std; using LL = long long; using ULL = unsigned long long; typedef pair P; constexpr int INF = 2000000000; constexpr int HINF = INF / 2; constexpr double DINF = 100000000000000000.0; constexpr long long LINF = 9223372036854775807; constexpr long long HLINF = 4500000000000000000; constexpr long long MMOD = 500000004; const double PI = acos(-1); int dx[4] = { 0,1,0,-1 }, dy[4] = { 1,0,-1,0 }; # define ALL(x) (x).begin(),(x).end() # define UNIQ(c) (c).erase(unique(ALL((c))), end((c))) # define mp make_pair # define eb emplace_back # define FOR(i,a,b) for(int i=(a);i<(b);i++) # define RFOR(i,a,b) for(int i=(a);i>=(b);i--) # define REP(i,n) FOR(i,0,n) # define INIT std::ios::sync_with_stdio(false);std::cin.tie(0) LL ans; int N, i, H, M, h, m; char c; int main() { cin >> N; for (i = 0; i> H>>c >> M >> h >>c>> m; if (H>h) { ans += ((24 - H + h) * 60 + (m - M)); } else if (H == h) { if (M>m) { ans += ((h - H) * 60 + (m - M)); } else { ans += ((24 - H + h) * 60 + (m - M)); } } else { ans += ((h - H) * 60 + (m - M)); } } cout << ans << endl; }