#include "stdio.h"

 #include "iostream"

 #define MAXNUM 30

 int FalseCoin(int coin[], int low, int heigh)

 {

 int i, sum1, sum2, sum3;

 int re;

 sum1 = sum2 = sum3 = ;

 if (low +  == heigh)

 {

 if (coin[low] < coin[heigh])

 {

 re = low + ;

 return re;

 }

 else

 {

 re = heigh + ;

 return re;

 }

 }

 if ((heigh - low + ) %  == ) //n是偶数

 {

 for (i = low; i < low+(heigh - low) / ; i++)

 {

 sum1 = sum1 + coin[i];

 }

 for (i = low + (heigh - low) /  + ; i < heigh; i++)

 {

 sum2 = sum2 + coin[i];

 }

 if (sum1 > sum2)

 {

 re = FalseCoin(coin, low + (heigh - low) /  + , heigh);

 return re;

 }

 else

 {

 }

 }

 else

 {

 for (i = low; i < low+(heigh - low) /  - ; i++)

 {

 sum1 = sum1 + coin[i];

 }

 for (i = low + (heigh - low) /  + ; i < heigh; i++)

 {

 sum2 = sum2 + coin[i];

 }

 sum3 = coin[low + (heigh - low) / ];

 if (sum1 > sum2)

 {

 re = FalseCoin(coin, low + (heigh - low) /  + , heigh);

 return re;

 }

 else if (sum1 < sum2)

 {

 re = FalseCoin(coin, low, low + (heigh - low) /  - );

 return re;

 }

 else

 {

 }

 if (sum1 + sum3 == sum2 + sum3)

 {

 re = low + (heigh - low) /  + ;

 return re;

 }

 }

 }

 int main()

 {

 int coin[MAXNUM];

 int i, n;

 int weizhi;

 scanf("%d",&n);

 for (i = ; i < n; i++)

 {

 scanf("%d",coin[i]);

 }

 weizhi = FalseCoin(coin, , n - );

 printf("在上述%d个银币中，第 %d 个银币是假的！\n",n,weizhi);

 system("pause");

 return ;

 }