C :

#include<stdio.h>   

int main(){ 
	int a,b,c;
	scanf("%d %d %d",&a,&b,&c);
	
	if(a < b){
		int t = a;
		a = b;
		b = t;
	}
	
	if(b < c){
		int t = b;
		b = c;
		c = t;
	}
	
	if(a < b){
		int t = a;
		a = b;
		b = t;
	}
	
	if(a - b == 1 && b - c == 1){
		printf("TRUE");
	}else{
		printf("FALSE");
	}

	return 0;
} 

Python :

a,b,c = map(int,input().split());
# a>b>c
if a < b:
    t=a
    a=b
    b=t 
if a < c:
    t=a
    a=c
    c=t 
if b < c:
    t=b
    b=c
    c=t
if a-b==1 and b-c==1:
    print('TRUE')
else :
    print('FALSE')