I try to output zeros in this case, but seems like I'm wrong
please show me some example
for example for this case
2
11
11

Edited by author 11.12.2007 21:50

Can someone give me a little hint, please ?

I've got wa#11. But all test in forum my prog give right answers. Please give me more testcase.

Is it:
1) A OR B (element-wise OR)
2) A + B (where A, B are numbers)
?..

I think my algo is correct but I still have WA 17.
I saw that some people had TLE 17, can anybody tell my what kind of test is it?

int main()
{
//    freopen("input.txt", "r", stdin);
    scanf("%d", &n);
    scanf("%s%s", a, b);
    FOR(i, n) a[i]-='0',b[i]-='0';
    REPD(i, n-1, 0) if(a[i]+b[i]==0 && b[i]==0){
        b[i]++;
        REP(j, i+1, n-1)b[j]=0;
        out();
        return 0;
    }
    REPD(i, n-1, 0)if(a[i]==0){
        a[i]=1;
        REP(j, i+1, n-1)a[j]=0;
        ZERO(b);
        out();
        return 0;
    }
    ZERO(a);ZERO(b);
    out();

    return 0;
}

If A = "010" and B = "010", then A + B = "100" ?

I think it's not clear enough that all sequences (especially result pair (a, b)) must have length n.

The first compatible pair when there is no pair greater than (p,q) is ('000000....00' , '0000000...00' ) , isn't it ?
I got WA test 22nd , please help me a bit .

Isn't correct answer for test
INPUT:
2
01
10

OUTPUT:
1
0
Instead of
10
00
Cause
1 < 10
and I don't see that anywhere is written that the pair of sequences (a,b) should be the same length as (p,q)

Are there sequences p and q compatible?