#pragma GCC optimize("Ofast") #pragma GCC target("avx2") char*mmap(); #define rd(v) long v=0;{int _c;while(_c=*rp++-48,_c>=0)v=v*10+_c;} #define wt(v) {long _z=v;do*--wp=_z%10+48;while(_z/=10);} char wbuf[1<<20]; #define min(a,b) (a<=b?a:b) #define max(a,b) (a>=b?a:b) int a[2001]; long dp[2001][2001]; main(){ char*rp=mmap(0l,1l<<20,1,2,0,0ll); rd(n); rd(m); for(int i=0;i