let line
function getStr(str){
let max = ''
for(let i = 0;i<str.length;i++){
for(let j = str.length - 1 - i;j>=0;j--){
let temp = str.substring(i,j);
if(temp!=''){
if(str.indexOf(temp) != str.lastIndexOf(temp)){
if(temp.length > max.length){
max = temp
}
}
}
}
}
return max.length < 3
}
while(line = readline()){
// 97-122 [a-z]
// 48 -57 [0-9]
// 65 -90 [A-Z]
let flag = false
let numberFlag = false
let upperFlag = false
let lowerFlag = false
let otherFlag = false
if(line.length > 8 ){
let arr = line.split('');
for(let i =0;i<arr.length;i++){
let code = arr[i].charCodeAt(0)
if(48 <=code && code<= 57){
if(!numberFlag){
numberFlag = true
}
}else if(65 <=code && code<= 90){
if(!upperFlag){
upperFlag = true
}
}else if(97 <=code && code<= 122){
if(!lowerFlag){
lowerFlag = true
}
}else{
if(!otherFlag){
otherFlag = true
}
}
}
}
let count = 0
if(numberFlag){
count++
}
if(upperFlag){
count++
}
if(lowerFlag){
count++
}
if(otherFlag){
count++
}
if(count>=3){
if(getStr(line)){
console.log('OK')
}else{
console.log('NG')
}
}else{
console.log('NG')
}
}