#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();

#define rd_skip() while(*rp++>=48)
#define rd(v) long v=0;{long _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);}
#define rep(v,e) for(long v=0;v<e;++v)
#define chmax(v,a) (v=v>=a?v:a)

long a[200000];

main(){
	char*rp=mmap(0l,1l<<25,1,2,0,0ll);
	rd_skip();
	long n=0;
	while(*rp){
		rd(p);
		a[p-1]=++n;
	}
	long z=0,s=0;
	rep(i,n){
		chmax(z,s-a[i]);
		s+=a[i];
	}
	char wbuf[64],*wp=wbuf+sizeof wbuf;
	wt(z);
	write(1,wp,wbuf+sizeof wbuf-wp);
	_exit(0);
}