935B - Fafa and the Gates - CodeForces Solution

def sum(n, S):
    out = 0
    
    i = 0
    j = 0
    Loc = "*"
    
    for c in S:
        
        if c == "U":
            i += 1 
        if c == "R":
            j += 1
            
        prevLoc = Loc
        
        if i > j and prevLoc != "L":
            if Loc != "*":
                out += 1 
            Loc = "L"
        elif i < j and prevLoc != "R":
            if Loc != "*":
                out += 1
            Loc = "R"
            
    return out
            
            
        
        
            
        
    return out
    
n = input()
S = input()
print(sum(n, S))