ZOJ 1003 Crashing Balloon

#include <iostream>#include <cstdio>#include <cstring>using namespace std;int A,B,ans;bool flag;bool fun(int b,int s,int n){    for(int i=n;i>1;i--){        if(s%i==0)            if(fun(b,s/i,i-1))return true;        if(b%i==0)            if(fun(b/i,s,i-1))return true;    }    if(s==1)        flag=true;    else if(!flag)        return true;    if(b==1&&s==1)        return 1;    return false;}int main(){    while(scanf("%d%d",&A,&B)!=EOF){        int a,b;        flag=false;        if(A>B)            a=B,b=A;        else            a=A,b=B;        ans=b;        if(!fun(b,a,100))            ans=a;        printf("%ld\n",ans);    }    return 0;}