#import <Foundation/Foundation.h>

int main(void){

    @autoreleasepool {
    
        NSStringEncoding enc = NSUTF8StringEncoding;
        NSFileHandle *stdin = [NSFileHandle fileHandleWithStandardInput];
        NSFileHandle *stdout = [NSFileHandle fileHandleWithStandardOutput];
        
        NSData *indata = [stdin readDataToEndOfFile];
        NSMutableString *str = [NSMutableString alloc];
        [str initWithBytes:indata.bytes length:indata.length encoding:enc];
        
        NSScanner *scan = [NSScanner alloc];
        [scan initWithString:str];
        
        NSString *n_str = [NSString alloc];
        [scan scanUpToString:@"\n" intoString:&n_str];
        NSInteger n = [n_str integerValue];
        
        [stdout writeData:[(n < 1200?@"ABC":@"ARC") dataUsingEncoding:enc]];
    }
    
    return 0;
}