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

#define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define wt(v) ({unsigned _z=v;do*--wp=_z%10+48;while(_z/=10);})
#define wt1(v) ({char wbuf[64],*wp=wbuf+sizeof wbuf;wt(v);write(1,wp,wbuf+sizeof wbuf-wp);})

int main(){
	rd_init();
	char*rp0=rp;
	int n=rd();
	int s[64];
	fstat(0,s);
	rp=rp0+s[12]-1;
	while(*--rp>=48){
	}
	++rp;
	int z=rd()-n;
	wt1(z);
	_exit(0);
}