import sys
readline=sys.stdin.readline

N=int(readline())
V,T=[],[]
for i in range(N):
    v,t=map(int,readline().split())
    V.append(v)
    T.append(t)
M=max(T)+max(V)
dp=1
for i in sorted([i for i in range(N)],key=lambda i:V[i]+T[i]):
    dp|=(dp&((1<<min(M-V[i]+1,T[i]))-1))<<V[i]
ans=0
for i in range(M+1):
    if dp&1<<i:
        ans=max(ans,i)
print(ans)