const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;
void async function () {
// Write your code here
const arr = [];
while(line = await readline()){
let newstr = line.split(" ");
if (newstr[1]) {
let num = parseInt(newstr[0]);
let value = parseInt(newstr[1]);
if (arr[num]){
arr[num] += value;
} else {
arr[num] = value;
}
}
}
arr.forEach((cell, index) => {
console.log(index, cell);
});
}()