Problem:
Score : 100 points

Problem Statement

We have five variables x_1, x_2, x_3, x_4, and x_5.

The variable x_i was initially assigned a value of i.

Snuke chose one of these variables and assigned it 0.

You are given the values of the five variables after this assignment.

Find out which variable Snuke assigned 0.

Constraints

The values of x_1, x_2, x_3, x_4, and x_5 given as input are a possible outcome of the assignment by Snuke.

Input

Input is given from Standard Input in the following format:

x_1 x_2 x_3 x_4 x_5

Output

If the variable Snuke assigned 0 was x_i, print the integer i.

Sample Input 1

0 2 3 4 5

Sample Output 1

1

In this case, Snuke assigned 0 to x_1, so we should print 1.

Sample Input 2

1 2 0 4 5

Sample Output 2

3

Solution in C (GCC 9.2.1) (judge verdict: Accepted)


#pragma warning(disable:4996)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <float.h>

#pragma region 定義
#define i_cin(X) scanf("%d", &X)
#define i_cin2(X,Y) scanf("%d %d",&X,&Y)
#define i_cin4(X,Y,Z,W) scanf("%d %d %d %d",&X,&Y,&Z,&W)
#define i_cin3(X,Y,Z) scanf("%d %d %d",&X,&Y,&Z)
#define l_cin(X) scanf("%ld",&X)
#define f_cin(X) scanf("%f",&X)
#define l_cin2(X,Y) scanf("%ld %ld",&X,&Y)
#define s_cin(X) scanf("%s",&X)
#define c_cin(X) scanf("%c",&X);
#define ll_cin(X) scanf("%lld", &X)
#define ull_cin(X) scanf("%llu", &X)
#define lf_cin(X) scanf("%lf", &X)

#define  i_cout(X) printf("%d\n",X)
#define  f_cout(X) printf("%g\n",X)
#define  i_cout2(X,Y) printf("%d %d\n",X,Y)
#define  l_cout(X) printf("%ld\n",X)
#define  s_cout(X) printf("%s\n",X)
#define  s_coutc(X) printf("%s",X)

#define  c_cout(X) printf("%c",X)


#define  ll_cout(X) printf("%lld\n",X)
#define  ull_cout(X) printf("%llu\n",X)



typedef long long  ll;
typedef unsigned long long  ull;

#define rept(x, s, n) for (int x = s; x < n; x++)

#define S_RTN(S)  s_cout(S);return 0


#define _itoa(A,N) sprintf(A, "%d", N);

int i_cins(int n, int* A);
int l_cins2(int n, long* A, long* B);
int s_dsort(const void* a, const void* b);
int s_asort(const void* a, const void* b);

int  _gcd(int a, int b);
int  _swp(int* a, int* b);
int _cknum(char* a, int n);
int _atoi(char* s, int len);


int s_asorts(const void* a, const void* b);
int s_dsorts(const void* a, const void* b);

//昇順
int s_asorts(const void* a, const void* b) {
	return(strcmp((char*)a, (char*)b));
}
int s_dsorts(const void* a, const void* b) {
	return(strcmp((char*)b, (char*)a));
}

int s_dsort(const void* a, const void* b) {
	return(*(int*)b - *(int*)a);
}
int s_asort(const void* a, const void* b) {
	return(*(int*)a - *(int*)b);
}
int l_cins2(int n, long* a, long* b) {
	int i;
	rept(i, 0, n) {
		l_cin2(*(a + i), *(b + i));
	}
	return 0;
}
int i_cins(int n, int* a) {
	int i;
	for (i = 0; i < n; i++) {
		i_cin(*(a + i));
	}

	return 0;
}
int _gcd(int a, int b) {
	int r, tmp;
	if (a < b) { tmp = a; a = b; b = tmp; }
	r = a % b;
	while (r) {
		if (!r) break;
		a = b; b = r;
		r = a % b;
	}
	return(b);
}
// puts("Yes\n") puts("No\n")
// scanf("%d.%d") 浮動小数点入力を整数２つで得る


//#define pai  3.1415926535      
#define deg_rad(X)  (X*(M_PI/180))

long _max(long a, long b) {
	return a > b ? a : b;
}
long _min(long a, long b) {
	return a < b ? a : b;
}
int _swp(int* a, int* b)
{
	int tmp;
	tmp = *b; *b = *a; *a = tmp;
	return 0;
}

int _cknum(char* a, int n) {
	int i;
	char t = '0';

	for (i = 0; i < n; i++) {
		if (a[i] < '0' || a[i]>'9') return 1;
	}
	return 0;
}


int _atoi(char* s, int len) {
	char tmp[20];
	memcpy(tmp, s, len);
	tmp[len] = 0x00;
	return (atoi(tmp));
}

//素因数分解　pf素数が入る　pc 素数の数
ll _pfact(ll a);
static ll pf[100000000];
static ll pc;

ll _pfact(ll a) {
	long i, r;
	if (a % 2 == 0) {
		pf[pc] = 2; pc++;
		return(_pfact(a / 2));
	}
	r = sqrt(a);
	for (i = 3; i <= r; i += 2) {
		if (a % i == 0) {
			pf[pc] = i; pc++;
			return(_pfact(a / i));
		}
	}
	if (a != 1) {
		pf[pc] = a; pc++;
	}
	return 0;

}


#pragma endregion

//ABC 170 A-
int main(void) {
	int x;
	for (int i = 0; i < 5; i++) {
		scanf("%d ", &x);
		if (!x) {
			i_cout(i + 1); break;
		}

	}
	return 0;
}


////ABC 96 B-Cut and Count
//static int x[24][2];
//int _cnt(int s);
//int _cnt(int s) {
//	int i,cnt=0;
//	for (i = 0; i < 25; i ++ ) {
//		if (x[i][0] == x[i][1]) continue;
//		if (s >= x[i][0] && s < x[i][1]) cnt++;
//	}
//	return(cnt);
//}
//int main(void) {
//	int n, i;
//	int s[101];
//	char a;
//
//	i_cin(n);
//	scanf("\n");
//	for (i = 0; i < n; i++) {
//		scanf("%c",&a);
//		s[i] = a - 'a';
//		if(x[s[i]][0] == 0)
//		   x[s[i]][0] = i;
//		else
//		   x[s[i]][1] = i;
//	}
//	//for (i = 0; i < 25; i++) {
//	//	printf("s:%d e:%d \n", x[i][0], x[i][1]);
//	//}
//
//	int ans = 0;
//	for (i = 0; i < n; i++) 
//		ans = _max(ans, _cnt(i));
//
//	i_cout(ans);
//	return 0;
//}
//

//ABC 065 B - Trained?
//int main(void) {
//	return 0;
//
//}

//ABC 133 C - Remainder Minimization 2019

//ABC 95-C Half and Half
//int main(void) {
//	long  a, b, c, x, y;
//	long tmp;
//	scanf("%ld %ld %ld %ld %ld", &a, &b, &c, &x, &y);
//	c *= 2;
//
//	/*if (a >= c) {
//		tmp=(long)x * c + ((y - x < 0) ? 0 :(long)(y - x) * b);
//		printf("%ld",tmp);
//		return 0;
//	}
//	if (b >= c) {
//		tmp =(long)y * c + ((x - y < 0) ? 0 : (long)(x - y) * b);
//	    printf("%ld\n", tmp);
//		return 0;
//	}*/
//
//	if ((a + b) <= c) {
//	     printf("%ld\n",a * x + b * y);
//	     return 0;
//	}
//	
//	tmp = a * x + b * y;
//	if (c * _max(x, y) < tmp) {
//		printf("%ld\n",c* _max(x, y)); return 0;
//	}
//
//	tmp = c * _min(x, y);
//	tmp += ((x < y) ? (y - x) * b :(x - y) * a);
//	printf("%ld\n", tmp);
//	return 0;
//}