#include #include using ll = long long; ll chmax(ll &x, const ll &y){ if(x < y) x = y; return x; } int main(){ int n, m; std::cin >> n >> m; ll plus = 0, minus = 0; for(int i = 0; i < n; ++i){ ll a = 0; for(int j = 0; j < m; ++j){ ll tmp; std::cin >> tmp; a += tmp; } chmax(plus, minus + a); chmax(minus, plus - a); } std::cout << std::max(plus, minus) % 1000000007 << std::endl; }