Function add

Codeforces_problems/Two Platforms/solution.cpp:53–53

#define FOR(i,j,k,l) for(int i=j;i<k;i+=l)
#define REP(i,j) FOR(i,0,j,1)
inline ll add(ll a, ll b){a += b; if(a >= MOD)a -= MOD; return a;}
inline ll sub(ll a, ll b){a -= b; if(a < 0)a += MOD; return a;}
inline ll mul(ll a, ll b){return (ll)((ll) a * b %MOD);}
typedef vector<ll> vl;