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')
        }
}