Problem:
Score : 100 points

Problem Statement

There is an N-car train.

You are given an integer i. Find the value of j such that the following statement is true: "the i-th car from the front of the train is the j-th car from the back."

Constraints

1 \leq N \leq 100

1 \leq i \leq N

Input

Input is given from Standard Input in the following format:

N i

Output

Print the answer.

Sample Input 1

4 2

Sample Output 1

3

The second car from the front of a 4-car train is the third car from the back.

Sample Input 2

1 1

Sample Output 2

1

Sample Input 3

15 11

Sample Output 3

5

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::io::*;                                                                                                                                                                                             
use std::str::FromStr;                                                                                                                                                                                      
                                                                                                                                                                                                            
fn read<T: FromStr>() -> T {                                                                                                                                                                                
    let stdin = stdin();                                                                                                                                                                                    
    let stdin = stdin.lock();                                                                                                                                                                               
    let token: String = stdin                                                                                                                                                                               
        .bytes()                                                                                                                                                                                            
        .map(|c| c.expect("failed to read char") as char)                                                                                                                                                   
        .skip_while(|c| c.is_whitespace())                                                                                                                                                                  
        .take_while(|c| !c.is_whitespace())                                                                                                                                                                 
        .collect();                                                                                                                                                                                         
    token.parse().ok().expect("failed to parse token")                                                                                                                                                      
}                                                                                                                                                                                                           
                                                                                                                                                                                                            
fn main(){                                                                                                                                                                                                  
    let n: u32 = read();                                                                                                                                                                                    
    let i: u32 = read();                                                                                                                                                                                    
    let ans = n-i+1;                                                                                                                                                                                        
    println!("{}", ans);                                                                                                                                                                                    
}