N,K=map(int,input().split()) AB=[list(map(int,input().split())) for i in range(N)] MIN=1 MAX=10**9 while MIN!=MAX: x=(MIN+MAX)//2 SUM=0 for l,r in AB: if xr: SUM+=(r-l+1) else: SUM+=(x-l+1) #print(x,MIN,MAX,SUM) if SUM>=K: MAX=x else: MIN=x+1 print(MIN)