let n = ~~readline()

let map = new Map()
let line
let key,num
while(line = readline()){
    [key,num] = line.split(' ')
    if (map[key]) map[key] += ~~num
    else  map[key] = ~~num
}

for(let key in map){
    console.log(`${key} ${map[key]}`)
}
//也可以用map.entries吧。