Sum of Three Terms(构造)

#define rep(i,l,r) for(int i=(l);i<=(r);i++) #define per(i,l,r) for(int i=(l);i>=(r);i--)
#define ll long long
#define pii pair
#define mset(s,t) memset(s,t,sizeof(t))
#define mcpy(s,t) memcpy(s,t,sizeof(t))
#define fir first
#define pb push_back
#define sec second
#define sortall(x) sor

Sum of Three Terms(构造)最先出现在Python成神之路。