Problem:
Score : 100 points

Problem Statement

There are two buttons, one of size A and one of size B.

When you press a button of size X, you get X coins and the size of that button decreases by 1.

You will press a button twice. Here, you can press the same button twice, or press both buttons once.

At most how many coins can you get?

Constraints

All values in input are integers.

3 \leq A, B \leq 20

Input

Input is given from Standard Input in the following format:

A B

Output

Print the maximum number of coins you can get.

Sample Input 1

5 3

Sample Output 1

9

You can get 5 + 4 = 9 coins by pressing the button of size 5 twice, and this is the maximum result.

Sample Input 2

3 4

Sample Output 2

7

Sample Input 3

6 6

Sample Output 3

12

Solution in C (GCC 5.4.1) (judge verdict: Accepted)


#define TEST_SNO	1
#define TEST_ENO	1
#define ll			long long

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

typedef struct data {
	int a;
	int b;
} data;

FILE *in, *ans;
int tno;

int out(const char *s) {
#ifdef TEST
	char buf[8192];
	fgets(buf, sizeof(buf), ans);
	if (strcmp(buf, s)) {
		printf("err\n");
	}
#else
	printf(s);
#endif
	return 0;
}

int outi(int i) {
	char s[128];
	sprintf(s, "%d\n", i);
	out(s);
	return 0;
}

int outll(ll l) {
	char s[128];
	sprintf(s, "%lld\n", l);
	out(s);
	return 0;
}

int geti() {
	int i;
	fscanf(in, "%d", &i);
	return i;
}

ll getll() {
	ll l;
	fscanf(in, "%lld", &l);
	return l;
}

int getstr(char *s) {
	fscanf(in, "%s", s);
	return 0;
}

int fnc() {

	int i;

	int a = geti();
	int b = geti();

	int s = 0;
	for (i = 0; i < 2; i++) {
		if (a > b) {
			s += a;
			a--;
		}
		else {
			s += b;
			b--;
		}
	}

	outi(s);

	return 0;
}

int main() {
#ifdef TEST
	for (tno = TEST_SNO; tno <= TEST_ENO; tno++) {
		char str[128];
		sprintf(str, "test%d.txt", tno);
		in = fopen(str, "r");
		sprintf(str, "ans%d.txt", tno);
		ans = fopen(str, "r");
		fnc();
		fclose(in);
		fclose(ans);
	}
	printf("end\n");
#else
	in = stdin;
	fnc();
#endif

	return 0;
}