#include #include #define mod 1000000007 using namespace std; int main(){ int n; unsigned long long ans = 0; cin >> n; long long c[n],d[n]; for(int i=0;i < n;i++){ cin >> c[i] >> d[i]; ans += (unsigned long long)ceil((double)c[i]/2)%mod * d[i]%mod; ans %= mod; cout << ans << endl; } cout << ans % mod << endl; return 0; }