#pragma GCC optimize("Ofast") #pragma GCC target("avx2") int a[301][45000]; #define MD 1000000007 main(){ a[0][0]=1; for(int y=1;y<=300;++y){ long t=1; a[y][0]=1; int xm2=y*(y-1)>>1; int xm1=xm2>>1; int x=1; for(;x