为什么我总是RE

#include<bits/stdc++.h>
using namespace std;
int a[4][4]={{0,0,0,0},
{0,1,2,3},{0,4,5,6},{0,7,8,9}};
int main(){
    long long n;
    cin>>n;
    bool flag=false;
    int cnt=0;
    while(n>0){
        cnt++;
        int t=n%10;
        int b=n/3;
        int c=n%3;
        if(cnt%2==1) a[b][c]=1;
        else a[b][c]=0;
    }
    if(a[1][1]==a[1][2]&&a[1][2]==a[1][3]){
        flag=true;
        if(a[1][1]==1) cout<<"xiaoa wins.";
        else cout<<"uim wins.";
    }
    if(a[2][1]==a[2][2]&&a[2][2]==a[2][3]){
        flag=true;
        if(a[2][1]==1) cout<<"xiaoa wins.";
        else cout<<"uim wins.";
    }
    if(a[3][1]==a[3][2]&&a[3][2]==a[3][3]){
        flag=true;
        if(a[3][1]==1) cout<<"xiaoa wins.";
        else cout<<"uim wins.";
    }
    if(a[1][1]==a[2][1]&&a[2][1]==a[3][1]){
        flag=true;
        if(a[1][1]==1) cout<<"xiaoa wins.";
        else cout<<"uim wins.";
    }
    if(a[1][2]==a[2][2]&&a[2][2]==a[3][2]){
        flag=true;
        if(a[1][2]==1) cout<<"xiaoa wins.";
        else cout<<"uim wins.";
    }
    if(a[1][3]==a[2][3]&&a[2][3]==a[3][3]){
        flag=true;
        if(a[1][3]==1) cout<<"xiaoa wins.";
        else cout<<"uim wins.";
    }
    if(a[1][1]==a[2][2]&&a[2][2]==a[3][3]){
        flag=true;
        if(a[1][1]==1) cout<<"xiaoa wins.";
        else cout<<"uim wins.";
    }
    if(a[3][1]==a[2][2]&&a[2][2]==a[1][3]){
        flag=true;
        if(a[1][1]==1) cout<<"xiaoa wins.";
        else cout<<"uim wins.";
    }
    if(flag==false) cout<<"drew";
    return 0;
}