def check_string(str1):
    
    messg = [
    lambda str1: any(x.isupper() for x in str1) or 'String must have 1 upper case character.',
    lambda str1: any(x.islower() for x in str1) or 'String must have 1 lower case character.',
    lambda str1: any(x.isdigit() for x in str1) or 'String must have 1 number.',
    lambda str1: len(str1) >= 7                 or 'String length should be atleast 8.',]
    result = [x for x in [i(str1) for i in messg] if x != True]
    if not result:
        result.append('Valid string.')
    return result  
def min_cost(cost, m, n):
	R = 3
	C = 3
	 
	tc = [[0 for x in range(C)] for x in range(R)] 
	tc[0][0] = cost[0][0] 
	for i in range(1, m+1): 
		tc[i][0] = tc[i-1][0] + cost[i][0] 
	for j in range(1, n+1): 
		tc[0][j] = tc[0][j-1] + cost[0][j] 
	for i in range(1, m+1): 
		for j in range(1, n+1): 
			tc[i][j] = min(tc[i-1][j-1], tc[i-1][j], tc[i][j-1]) + cost[i][j] 
	return tc[m][n]